Nida 12a - Hargasha Without Seeing Blood

The Shulchan Aruch (190:1) cites the Terumas HaDeshen that if a woman were to have a hargasha (a sensations that would indicate bleeding - see pischei teshuva for 3 types), she must assume that she bled even though she didn't notice any blood. The rationale is that the Hargasha itself is evidence that there was actual bleeding.

Rav Zeira asks whether a woman who is not involved in taharos should examine herself prior to relations before being with her husband. R. Abba asks whether she should examine herself after having relations to figure out whether they need to bring a korban. The gemara responds to both questions by saying that she shouldn't examine herself because if she would, he would be hesitant to have relations with her. Rashi (d.h. im kein) seems to interpret the gemara to be questioning whether chazal impose such an examination on her. According to this approach the response of the gemara is that by Chazal imposing a requirement to do a bedika, they are indicating that there is a concern that she will bleed, this will cause him to abstain from having relations with her. However, if she were to decide to do a bedika on her own, we wouldn't stop her. Tosafos on the other hand seems to indicate that by her doing a bedika, even as a chumra, would indicate that she must have had a hargasha and cause him to abstain from relations with her. Why would he abstain from relations? Let her do a bedika and if it's clean it would indicate that she is not a Nidah. It seems that Tosafos supports the opinion of the Terumas HaDeshen and if she were to have a hargasha, even if followed by a clean bedika, she would be considered tamei. Therefore we are afraid that he will abstain from relations even if the bedika is clean out of fear that she had a hargasha.

Meilah 16b - Shiur for Eating Sheratzim

Rav says that to receive malkus for eating sheratzim, one must eat a kezayis. Since the Torah uses the term "achila" it follows the rule of all issurim that malkus requires a kezayis. The gemara challenges this from a braisa that compares the issur achila to tu'mah which is b'kadasha (lentil), and concludes that when one eats a live sheretz the shiur is kezayis, but a dead one on which there is tu'mah for the size of a lentil, one would also receive malkus for consuming the size of a lentil. This distinction is paskened in the Rambam, but not explicitly paskened in shulchan aruch since even a chatzi shiur is forbidden, and the only application is for malkus.

In truth, this issue is paskened in shulchan aruch and even has a practical application. In Y.D. 104:1, the Shulchan Aruch discusses עכברא בשכרא, a rodent that falls into beer. The Shulchan Aruch writes that even if there is 60x to be mevatel the rodent, if there are pieces of it in the food that it fell into so that it can be felt upon chewing, although it is unable to be separated out, it makes the entire food forbidden. There is a big dispute between the Taz and Shach as to the rationale for this prohibition. The Taz understands this to be a rule with all non-kosher items that fall into a food from which they cannot be separated but are distinguishable when eating it, that they aren't batul. It wouldn't matter how small the pieces are, they wouldn't be batul (the Taz continues to qualify this  - we are only concerned if there is a possibility that one will be eating the issur standing alone without the mixture of the kosher food). However, the Shach understands that this is an issue specific to one of the 8 sheratzim that the Torah forbids. The nature of this halacha is that since the shiur for malkus is k'adasha, the size of a lentil, we are extra strict about allowing it to be eaten through bitul. Since there is malkus for the size of a lentil we treat it like a בריה and don't allow it to be batul. Therefore, according to the shach if the pieces were smaller than the size of a lentil, or by other issurim even if the pieces were larger than a lentil, it would be batul and permissible.

This issue may really be a machlokes between rashi and the Ran. Rashi explained that the stringency of the sheretz has something to do with the shiur of malkus being the size of a lentil, but the Ran asks what do we need that for, just say it is because of חצי שיעור אסור מן התורה. The Shach explained that by other issurim we wouldn't be machmir since they are nosein ta'am l'fgam and the actual issur is batul, it is only for a sheretz where the shiur is k'adasha that we are machmir. The Mateh Yehonassan suggests that chatzi shiur that falls into a mixture no longer retains it's status of issur, unless one could consume a kezayis within an achilas p'ras. Therefore, issurim for which one can eat a shiur is not going to be batul even if there is less that a kezayis in an achilas pras. That is why we are machmir for a sheretz because even if there is less than a kezayis in achilas pras, it would still retain its status of issur so long as one can eat a lentil size of it within an achilas p'ras (it would be like any other issur in which there was a kezayis in an achilas pras).

Krisus 10a - Opening of Uterus Will Always Cause Bleeding

I previously posted about this topic HERE and explained the position of Rav Moshe who assumes it is the size of a pinkie finger making the diameter to be about 7mm (and maybe even 1cm which is 10mm).

Rav Moshe says that aside from the Mishna in Ohalos which gives an unfamiliar shiur and assumes that it would be larger than the size of one's pinkie. However, in our gemara it discusses a woman who miscarries a 40 day old fetus as a dry birth which doesn't render her tamei. The gemara asks that the opening of the uterus should definitely cause some blood, to which the gemara concludes that it must be אפשר לפתיחת הקבר בלא דם. This would be the source of the Rambam to reject the entire notion of אי אפשר לפתיחת הקבר בלא דם, because the gemara would clearly be saying that it is possible. However, the gilyon hashas quotes an alternate girsa from the Rashba. The gemara thought that even the opening of the uterus caused by a 40 day old fetus should be considered an opening of the uterus for the purpose of assuming there will definitely be blood, to which the gemara responds that since the fetus at 40 days is so small, it won't cause bleeding. The girsa of the Rashba actually states clearly that the size of the fetus at 40 days is exactly the shiur for this assumption of אי אפשר לפתיחת הקבר בלא דם. According to ultrasound measurements that we are privy to nowadays and scientific estimations, a fetus that is between 5 and 6 weeks from conception will be between 2mm and 4mm in size. Therefore it should follow that any time a physician inserts an instrument with a diameter larger that 4mm into the uterus we would have to say אי אפשר לפתיחת הקבר בלא דם and render her tamei. This is a big chumra because it reduces the shiur of R. Moshe by half and seems much clearer that trying to estimate the shiur referenced in the mishna in ohalos.

Temurah 31a - Animal that is raised on non-kosher food

The Mishna says that an animal that nurses from a treifa mother is forbidden to be used as a korban. The gemara qualifies that it cannot mean that animal that gained a few pounds by eating non-kosher food becomes assur. The gemara explains that we are speaking about an animal that nurses daily from a treifa animal an amount that is sufficient to sustain it entirely, therefore even if the animal eats other things, it is forbidden to be brought as a korban.

The Mishna implies that an animal sustained primarily from issur food is forbidden as a korban, but permitted to be shechted and eaten. However, Tosafos writes - ולפום ריהטא אפילו להדיוט, meaning that it seems it would be forbidden even for a regular person to eat. The Rama in Shulchan Aruch (Y.D. 60:1) follows Tosafos and writes an animal that ate non-kosher is permitted, but אם לא נתפטמה כל ימיה רק בדברים אסורים אסורה - if it only ate issur it's entire life, it becomes forbidden. The Pischei Teshuva cites the Levushei Sered who suggests that this is a fixable problem. If one were to feed the animal kosher foods for a few days, it would lose it's status as an animal that was raised it's entire life on non-kosher foods.

The difficulty with both Tosafos and the Rama is that the mishna implies that this is a problems specifically for korbanos. If this were an issue with even chulin animals forbidding them to be eaten, why would this halacha be said in the context of korbanos? The Gr"a deals with this question and suggests that the Mishna and Gemara are speaking about an animal that primarily is sustained by forbidden food (such as milk from a treifa) but throughout the course of the day will also eat other things. In that circumstance it is forbidden for a korban since the non-kosher milk is sufficient to sustain the animal without any other food, but is not forbidden to be eaten. The Rama is speaking about an animal that ONLY ate non-kosher foods and then becomes forbidden even for a regular person so shecht ant eat it. According to the Gr"a it would seem that that one can certainly do as the Levushei Sered suggests, to feed the animal kosher food for a couple of days and then shecht it to eat.

Temurah 30b - Having relations with one's wife while pregnant

Rava says that if one were to commit bestiality with an pregnant animal, the fetus will also assume a status of "nirva" and be forbidden to be brought as a korban because היא וולדה נרבעו. The gemara explains that this issue is dependent on the notion that the child is a "limb" of the mother - עובר ירך אמו הוא, therefore anything done to the mother is as if it were done to it's child. Based on the same rationale, if a pregnant animal kills, the fetus is also considered a "no'geiach" and killed. Since the fetus is part of the mother it is as if it participated in the actions of the mother. 

R. Akiva Eiger (Kesavim 172) asks a very strange question. Based on the rationale of the gemara that היא וולדה נרבעו, it should be forbidden for one to have relations with their pregnant wife since it is tantamount to having relations with their own child? R. Akiva Eiger offers a technical answer. Since chazal don't consider it to be an act of relations when a girl is less than 3, it wouldn't be a torah violation. Although it would normally be a Rabbinic violation to have relations even with a girl less than 3, the violation is based on wasting seed which obviously doesn't apply when he is having relations with his pregnant wife. In short, R. Akiva Eiger considers having relations with one's wife while pregnant to be having relations with the fetus itself.

The Yachin Bo'az says that R. Akiva Eiger's entire approach doesn't make sense. If we truly consider every act done to the mother as if it were done to the child, there should be a violation to shecht the mother since it is as if he were shechting the mother and child on the same day. The Tiferes Yisroel (Boaz) explains that the answer lies in the gemara's assumption that עובר ירך אמו. Since the fetus is considered part of the mother it is not considered to be having relations with the fetus, just with the mother. The concept of היא וולדה נרבעו doesn't mean that it is as if he committed the aveira with both the mother and the child, but rather since the child was part of the mother at the time of the aveira, it assumes whatever status the mother has. The concept of עובר ירך אמו הוא doesn't make it as if he were having relations with the fetus, rather it makes that the relations he had with the mother causing it to assume a status of a נרבע would also apply to the fetus. In a situation where there is no status placed on the mother, there is no effect at all on the child. According to this approach the phrase היא וולדה נרבעו isn't to be taken literally, it is merely an expression meant to convey that the status of the mother will apply to the child as well.

Temurah 16a - Halachos Forgotten in Aveilus of Moshe

The gemara says that 3000 halachos were forgotten when Moshe died. The people asked Yehoshua to retrieve the lost halachos from Hashem to which he responded לא בשמים הי. Generations later they asked Shmuel to retrieve it, to which he responded אלה המצות - שאין נביא רשאי לחדש דבר מעתה. Both responses seem to be similar, the only Navi who is able to transmit Torah from Hashem is Moshe. Once it was transmitted by Moshe, it was not simply shared with the Jewish people, but literally given to the Jewish people so that all decisions had to take place following a halachic system. The only way to retrieve lost halachos is to do as Asniel Ben Kenaz did, to use principles available and analysis (piplul) to retrieve the lost information. Even when machlokes develops, the only way to decide who is correct is using the system of אחרי רבים להטות as the gemara says was done after Moshe died - אם רבו מטמאין טמאו, אם רבו טהורין טיהרו (although rashi explains that the machlokes about semicha was the first machlokes ever to exist, that means it was the first machlokes where they couldn't reach an agreement by voting, but surely there was machlokes much earlier - the gemara in Sanhedrin (2nd perek) suggests that Shaul and Dovid had a halachic debate about המקדש במלוה).

It is unclear from the gemara why when Yehoshua was asked to retrieve the halachos his response was לא בשמים היא, whereas Shmuel responds אלה המצות - שאין נביא רשאי לחדש דבר מעתה, since they are essentially the same point. The Maharsha asks this question as suggests that for Yehoshua it may not have been a violation of אלה המצות since he had heard these halachos from Moshe himself, just that he forgot them. He needed to be reminded of them, but didn't need to learn them from scratch. Therefore, it wouldn't be a violation of introducing something new, nevertheless couldn't be done due to the limitation of לא בשמים היא.

The gemara in Megilla 3a says that the "tzofim", meaning the nevi'im, introduced the מנצפ"ך, meaning all the letters that have a different font when they appear at the end of a word. The gemara asks how could the nevi'im have introduced something so fundamental, it is a violation of אלה המצות - שאין נביא רשאי לחדש דבר מעתה. The gemara answers - שכחום וחזרו ויסדום. Originally, they were given by Moshe, but they were lost and the nevi'im were used to retrieve the lost halachos. This clearly implies that even when Nevi'im restore lost halachos that they have never heard before, it isn't a violation to אלה המצות. Why does our gemara consider the restoring of forgotten halachos to be a violation of אלה המצות?

It seems that the answer lies within the words of Rabbeinu Chananel in Megillah who writes:

ואקשינן ואלה המצות שאין נביא רשאי לחדש דבר מעתה, ופרקינן לעולם מתוקנים היו, וכן היה מסורת בידם מהנביאים להיות הפתוחים באמצע תיבה והסתומים בסוף תיבה, ושכחום וחזרו הצופים ויסדום

Rabbeinu Channanel seems to explain that they had a mesorah from the nevi'im about these letters and exactly where they should be placed, the function of the nevi'im who restored them was only to remind people of the mesorah. It seems from here that once it has entered the chain of mesorah, it can be restored by nevi'im, but when taught by Moshe and immediately forgotten, since it never entered the realm of מסרן ליהושע ויהושע לזקנים וזקנים מסרוה וכו, it can't be restored by nevi'im.

Temurah 14b - Reciting written Torah by heart

The gemara says that oral torah cannot be written, and written torah cannot be recited by heart. It compares one who writes halachos to one who burns a sefer torah. Rashi explains that if a fire would break out on shabbos it would be forbidden to violate shabbos to save the sefer of halachos, therefore the initial writing of it causes it to be burned. Rashi offers a second interpretation that it is destructive to the oral Torah to commit it to writing. The second explanation is difficult, why is it equivalent to burning of a Torah? It seems that the problem with writing oral torah is that it make what should be infinite into something limited and finite. Therefore, by writing halachos one is inherently considering it to be no longer disputable and no longer open for debate. He is "burning" the torah that could have been discussed and introduced on this topic by committing the torah to writing. The exception to this rule the gemara says is when one writes a chiddush that presumably would otherwise be forgotten. The writing of a chiddush is necessary for the preservation of torah and therefore wouldn't be a violation of writing what shouldn't be written.

Similarly, one is not allowed to read the written torah by heart. Tosafos asks from various written sections of the Torah that were accustomed to being recited by heart in the context of davening. Tosafos answers that it is only problematic when one recites a written section by heart with the intent of being motzi someone in their obligation i.e. reading krias shema for someone who is going to be yotzei through sho'meia k'oneh. Tosafos also limits the violation to chumash as opposed to nevi'im and kesuvim.

The Shulchan Aruch (O.C. 49) says that sections which people are familiar with such as shema and birchas kohanim one is allowed to do by heart, but doesn't quote Tosafos who permits anything which is not being done to be motzi others. The rationale of the Shulchan Aruch seems to assume that the problem is that we afraid of one making an error and misquoting from torah she'bichsav, therefore things which are well known are permitted. This is also the implication of the biur halacha citing Tosafos Yeshanim to permit reciting hallel by heart. However, the limitation of Tosafos to when one is being motzi others seems to be that when done casually and not to be motzi someone's obligation, it isn't significant enough to qualify as a prohibition.

The Mishna Berura uses Tosafos as cited by the Gr"a and Radvaz to permit one to read the parsha along with the ba'al koreih even though they don't have a chumash open in front of them. The M.B. also quotes from the chavos ya'ir to permit one to recite tehillim by heart combining the heter of the chavos ya'ir that it qualifies as tefilla and the heter of tosafos that one isn't being motzi others. It is interesting that they don't quote the other distinction of tosafos who limits the prohibition to chumash.

Temurah 8a - Not to sell a bechor or ma'aser in the market

The Mishna in Bechoros 31a says that one is not allowed to sell the meat of a bechor or ma'aser b'heima on the regular meat market because the extra money gotten from selling on the market will only benefit the owners but in no way benefit hekdesh (to the exclusion of pesulei hamukdashin where the original redemption price will be determined by how much the meat can be sold for so hekdesh will benefit). By making the heter to sell in the market dependent on whether hekdesh benefits indicates that the issur is only d'rabonon. However, Tosafos in Bechoros proves from or sugya that it must be d'oraysa because the gemara says that since it has these halachos restricting their sale, it is not included in the word בהמתה by an עיר הנדחת because we only include things that can be eaten בתורת בהמתה. If these restrictions would only be d'rabonon, it wouldn't make sense to exclude it from עיר הנדחת based on a pasuk. Tosafos isn't sure what the pasuk would be to forbid this and suggests that there must be some pasuk that forbids degrading hekdesh unless there is a gain for hekdesh. Perhaps the source of this can be the gemara 7a that says that being makdish a ba'al mum is a violation of לא תקריבו even though it only assumes status of kedushas bedek habayis because it is degrading to hekdesh to be makdish a ba'al mum since within the same species there are animals that are fit for a korban - בזיא מילתא וכו' כיון דאיכא במינו. Since the nature of this issur is the degrading of hekesh, perhaps it can be expanded to include the degrading of bechor and ma'aser meat by being sold on the open market.

The Minchas Chinuch (361) cites Tosafos in Zevachim who says that according to some the prohibition is only d'rabonon as the simple reading of the Mishna would imply. If the nature of the prohibition is only d'rabonon, how are we to explain our gemara that exempts it from the שלל עיר הנדחת based on these prohibitions? The gemara darshens from בהמתה to exclude anything that isn't eaten as a regular animal. Although the restrictions against selling and weighing are only Rabbinic, the fact of the matter is that it isn't able to be eaten the way a regular animal is and is therefore excluded from ir ha'nidachas. The Torah may not recognize the Rabbinic issur but nevertheless excludes anything which is practically and actually not treated as a regular animal.

Temurah 4b - When the Torah says not to do it, does it work anyway?

The gemara launches into a major discussion about the concept of כל מילתא דאמר רחמנא לא תעביד, אי עביד לא מהני. Meaning, when the Torah says not to do something, is there a built in mechanism that makes it ineffective even if it is done (rava), or is it effective. The gemara explains that according to Abbaye it must be effective because otherwise there was nothing violated for which to receive malkus, but according to Rava the malkus is for performing the action that the Torah said not to, but it will not be effective.

R. Akiva Eiger (Comments to Y.D. 10:1) explains that the application of this concept is only in cases where by the Torah saying it doesn't work, the Torah is accomplishing something. Meaning, there is a preventative clause built in to any aveira that if the issur can be reduced by it not going into effect, the Torah doesn't enable the issur to go into effect. For example, if one were to shecht on shabbos, the concept of אי עביד לא מהני would not apply to invalidate the shechita because even if the shechita were invalidated, it would in no way reduce the violation of shabbos. We can only apply this concept to a places where by invalidating the effect, it would lessen the violation such as divorcing a woman who one raped. The Torah doesn't want her to be divorced so by invalidating the divorce, the violation is lessened (but the gemara learns from a pasuk that the this is an exception to the rule and the divorce is binding).

Therefore, R. Akiva Eiger asks that if one would shecht an animal with a knife that is forbidden to benefit from because it is avoda zarah, it would make sense to apply אי עביד לא מהני to invalidate the shechita. The benefit from the knive is dependent on the shechita being valid, therefore invalidating the shechita would prevent the violation of benefiting from the knife. R. Akiva Eiger points out based on the Turei Even in Rosh Hashana that even Abbaye who holds אי עביד מהני would only say that in a situation where even if we undermine the effect of the issur, it doesn't negate the fact that he violated the din of the torah. In other words, since even after we undermine the effect of the issur, he nonetheless violated the מימרא דרחמנא (for which rava says he gets malkus), there is no point in negating the effect of his actions since it doesn't truly rectify the violation. However, in a case where undermining the effect will completely undermine the violation, even Abbaye would agree that we apply the concept of אי עביד לא מהני. Therefore, when one shechts with a knife that they are forbidden to derive benefit from, by invalidating the shechita and rendering the animal a ne'veila, we are completely circumventing the violation becasue the violation is not to do an action, it is to benefit. By rendering the animal a neveila it comes out that he never even violated the מימרא דרחמנא so even Abbaye should agree that the animal is considered a ne'veila. R. Akiva Eiger leaves with at צריך עיון.

Erchin 30a - Who can redeem at a prorated rate?

The mishna has various restrictions regarding the rules of redeeming. For example, one cannot sell another property or borrow to obtain capital with which to redeem. Also, one is not allowed to redeem just a piece of the property, they need to wait until they have enough to redeem the entire amount. There is also a system of calculating the redemption price by dividing the sale price by the number of years (with a few more details to compensate for fluctuations in the price of the property, and if it is resold at a different price), from hereon in referred to as prorating. The Rashash questions whether these details of redemption apply specifically to the owner of the property or even to his relatives when they redeem in his place. The Rashash quotes from Toras Kohanim that all the rules apply to the relatives also, except for the concept of prorating which only applies to the actual owner. The Rashash says that the pesukim clearly imply "to one who has a sharp eye" that only for an owner do we prorate to force the buyer to sell him his field back, but when a relative redeems we don't impose this on the original buyer, rather we make the relative redeem at full price.

The Torah talks about prorating both in the context of an inherited field (Parshas Behar 25:25-27) and when one is sold to a ger toshav (48-50). In both places the torah first speaks about relatives redeeming for him but then says that if he comes across money so that he can redeem it by himself or redeem himself, the price is prorated. From this the Rashash understands that it is only prorated when he redeems, not when his relatives redeems.

However, the Meshech Chochma seems to take for granted that even when relatives redeem it is prorated. He asks why does the Torah speak first about relatives redeeming and then about redeeming himself. If relatives can redeem him, surely he can redeem himself when he gets the money together. The Meshech Chochma suggests based on chazal who understand from the pesukim that the prorating must be done meticulously so that the buyer is not being cheated in any way. Therefore, it first says that when relatives redeem we have to be careful to make sure the buyer isn't cheated. Even if the seller himself redeems, he is required to be meticulous about the calculation and not cheat the buyer. The Meshech Chochma seems to understand that both the redemption of the seller and the relatives are included in the system of prorating (unlike the rashash) but it is more of a chiddush to say that even the seller himself must be meticulous about the calculation.

Erchin 16a - Loshon Ho'rah in the Presence of Three

I already blogged about this previously and presented the different approaches - SEE HERE.

Reading the gemara simply, it seems to imply like the approach of the Rambam that once loshon hora was violated in the presence of 3 people, it can be assumed that it is already public info (even though the way it becomes public info is through an issur being violated) and can be said over by the 3 who heard it.

Being that the heter is based on the assumption that the word will get out, the Chofetz Chaim (perek 2) has many stipulations as to when it will be permitted:

1. It can be told over casually but not with the intention of spreading the news further. The Yad Ketana holds that even when said casually, it can only be said if that was the topic of conversation, but one cannot move the conversation in that direction in order to share the loshon hora.

2. It cannot be repeated back to the one it was said about. Although the Rashbam permits even this and doesn't consider it to be a violation of rechilus, the chofetz chaim isn't willing to pasken like that.

3. Only one who was part of the group of 3 can say it over, but not the person who heard it from him until it has become well known information.

4. If any of the group of 3 are exceptional yarei shamayim who wouldn't repeat it over, it cannot be repeated over by anyone in the group. He learns this from the gemara in sanhedrin 29a that considers the judges revealing their votes to be loshon hora even though the 3 judges know about it. He suggests that if any of the 3 wouldn't repeat it over because they are the subjects friends or family, it also cannot be repeated.

5. It can only be repeated to places where the news would have spread such as within the city. Mostly likely this condition no longer applies since information spreads very quickly to the 4 corners of the world.

6. If the original person who told it over warned the 3 listeners not to say it, one cannot assume that it will spread and cannot repeat it.

7. One cannot embellish the story in any way. It has to be said exactly as it was heard.

8. The heter is only for the one saying it over, but the listener still cannot believe it as factual. Therefore if the one telling it over knows the nature of the listener and that he would accept it as fact, he cannot tell it to him.

Erchin 10b - Hallel on Yetzias Mitzrayim

The gemara offers 3 explanations for why we don't say Hallel on Purim. 1. We don't say Hallel for a miracle that occurs outside of E.Y. after the Jews have already entered E.Y. 2. The reading of the Megilla is in place of the Hallel. 3. It wasn't a complete redemption since we remain slaves to Achashveirosh. The entire question as to why we don't say Hallel on Purim is predicated on the gemara's answer that we do say Hallel on Chanuka due to the miracle, even though it isn't called a Mo'ed and there is no prohibition of work. Therefore, all the distinctions as to why we don't say Hallel on Purim, do not apply to Chanuka. It is a miracle that occurred in E.Y., there is no reading to be in place of Hallel, and it was considered a "complete" redemption (although short lived - approx. 200 years). Rashi in Ta'anis 28b seems to understand that the reciting of Hallel on Chanuka would be considered d'oraysa, since the concept of saying of Hallel on a miracle is a Torah requirement.

The gemara challenges the first distinction between Chanuka and Purim from the fact that we say Hallel on the miracle of yetzias mitzrayim (and is forced to respond that prior to entering E.Y. we say hallel on chutz la'aretz miracles). It isn't clear from the gemara which Hallel it is referring to that is said for yetzias mitzrayim. The Turei Even in Megillah explains that it can't be referring to Hallel said on the first day of Pesach because that is a Hallel for the Yom Tov, not for the miracle. Therefore, he suggests that it is referring to the Hallel on the night of Pesach. The Mahartz Chiyus (here) understands the Turei Even to be speaking about the Hallel in shul on the night of Pesach because the Hallel in the Hagada is interrupted by the meal and wouldn't qualify as Hallel. The Maharatz Chiyus asks that to be referring to the Hallel said in shul on Pesach night is also difficult because the minhag ashkenazim based on the Rama is not to say it. It seems to me that the Turei Even is referring to the Hallel said within the Hagada. Although it is not said as a complete entity and wouldn't qualify as a "Hallel", it would nonetheless qualify as a "shira" and would prove that we do say shira even on a chutz la'aretz miracle.

The Rambam (Hil. Chanuka 3:6) paskens like the middle answer of the gemara - קריאתה זו היא הלילא. The Hallel of Chanuka is achieved by the reading of the megillah. This raises a big discussion in the poskim (sha'arei teshuva) in Hilchos Purim, if one doesn't have a megillah to read on Purim, should they recite the full Hallel (and perhaps even with a bracha). However, it seems that when the gemara says that megilla is in place of Hallel it doesn't just mean that it fulfills the obligation of Hallel, rather that reading the megilla is the expression that chazal instituted as the hallel for purim. Therefore, even if one were not to have access to a megilla they couldn't recite hallel with a bracha (and couldn't say a full hallel) since there was no takana to say hallel on purim.

Erchin 7a - Brain Death

The gemara says that before beis din would carry out capital punishment on a pregnant woman, they would kill the fetus inside of her to prevent the nivul that would occur if they were to kill her first. The gemara concludes from this that if they would first kill her, she would die before the fetus. However, the gemara asks from a source that indicates that a fetus would always die prior to the woman carrying it. The gemara reconciles this by making a distinction between a woman who is murdered in which case she may die first, and a woman who dies naturally in which case the fetus will ALWAYS die first.

It is reported that this gemara was a strong indication for Rav Shlomo Zalman to reject brain stem death as being dead. Since a brain stem dead patient can carry and deliver (Cesarean) a child, it must not be considered dead because it would contradict the gemara's rule that the child will always die before the mother. The fact that the mother can be brain dead and deliver a healthy child indicates that brain death is still alive.

However, in the very next line the gemara says that shabbos may be violated to save the unborn fetus of a pregnant woman who died in childbirth. The implication is that although she died naturally, her fetus may still be living. Rashi comments that sometimes the mother will die before the fetus which creates a safeik pikuach nefesh that justifies the violating of shabbos to save the fetus. According to Rashi it seems that there cannot be a rule that a mother will always die before the child. This would certainly undermine Rav Shlomo Zalman's assumption because the fact that a viable child may be born from a brain dead patient would not prove that brain stem death is still considered living. In truth, Rashi's approach is quite difficult. Just as we are able to assume in the case of inheriting from the mother to bequeath to the father's relatives, that fetus perished before the mother based on the rationale of the gemara - איידי דוולד זוטרא חיותיה עיילה טיפה דמלאך המות ומחתך להו לסימנין, we should be able to rely on that assumption for shabbos as well. Yet, Rashi would seem to hold that we can make that assumption when dealing with monetary issues but it will not be overwhelming enough to prevent an attempt at saving the fetus on the chance that it outlived the mother.

The Shita Mi'kubetzes (15) reconciles the apparent contradiction with a smoother approach. The Shita explains that when a woman is carrying a child but hasn't yet gone into labor, any natural cause of death would affect her fetus before it affects her, therefore her fetus will die first. But, when she has already gone into labor and the fetus has gotten some degree of independence, it is possible and even likely that the fetus will be able to live even after the mother has died (therefore permitting the violation of shabbos to save the fetus). According to this approach the original rule remains strong that prior to labor, when a pregnant woman dies a natural death, her fetus will always die before she dies. Therefore, it is reasonable for Rav Shlomo Zalman to assume that if a brain dead woman can "live" on life support for weeks until her baby is born, it is an indication that she isn't truly dead because a dead woman cannot produce a live baby.

Many years ago, there was an experiment done in Israel led by Dr. Avrohom Steinberg (a proponent of brain stem death being halachic death) to disprove Rav Shlomo Zalman's source. The experiment involved decapitating a pregnant sheep while hooked up to a heart-lung machine, and then successfully delivering a live lamb. There is no debate that a decapitated person or animal is considered dead, yet the baby lamb was able to outlive the trauma of the mother's decapitation. What does this prove? Seemingly it would prove that the gemara's principal is outdated. In the time of the gemara the rule may have been true that a fetus cannot remain alive after it's mother has died, but with modern technology it is a possibility. Therefore, the gemara would not disprove the concept of brain stem death being halachic death.

The problem with this experiment (which i surprisingly couldn't find discussion about) is that the gemara itself differentiates between natural death and one who is killed. The gemara accepts that when one is killed, the fetus can outlive it's mother. It is only when the mother dies through natural causes that the fetus must die first. Therefore, the sheep experiment would concur to the gemara's principal that killing the mother would not kill the fetus, yet when the mother would become brain dead without the trauma of being murdered, it would still be a viable source that brain death is not halachic death. It is unclear to me what exactly this experiment was meant to prove. It seems that the experiment wasn't meant to technically undermine the proof from our gemara. Rather the experiment was just meant to show that the heart and lung can continue to work well after decapitation, proving that life cannot be determined by heart and lung functionality.

For Dr. Steinberg's presentation of the experiment to Rav Shlomo Zalman, CLICK HERE. For an easier read and more cynical article detailing Israeli politics on this issue that was printed in Ha'aretz in english CLICK HERE.

Erchin 3b - Chatzitza for Tefillin

The gemara says that without a mishna explicitly obligating kohanim to wear tefillin, we would have thought that they were exempt from the head tefillin while doing the avoda. The rationale is that since they cannot wear the arm tefillin while wearing bigdei kehuna because it will be a chatzitzah, they should also be exempt from the head tefillin, therefore we require a mishna to say that they aren't exempt from the head tefillin. It is clear from the gemara that while doing the avoda the kohanim were not able to wear the arm tefillin. There are techincally two options regarding the arm tefillin. Either to wear it under the bigdei kehuna which the gemara rejects due to the chatzitza or wear it over the bidgei kehuna which rashi and tosafos both reject because והיה לך לאות ולא לאחרים לאות, meaning that the tefillin shel yad must be covered and not exposed.

The Rashba in a Teshuva (תרכ"ז) permits one to wear tefillin even if there is something separating between the tefillin and his skin. He derives this from the fact that the only problem that rashi and tosafos mention with putting tefillin on top of the bigdei kehuna is that tefillin shel yad can't be exposed, it must be hidden. This implies that we aren't concerned for chatzitza and for tefillin shel rosh which should be exposed, there is not issue at all with placing them on top of something else. The Shulchan Aruch (27:5) relies on the Rashba for one who has a head injury to put the tefillin shel rosh on top of a bandage or thin cap (without a bracha). The M.B. (18) similarly permits one to put tefillin shel yad on top of a bandage (without a bracha) relying on the rashba when there is no alternative. However, under normal circumstances the Shulchan Aruch (4) writes that chatzitza is an issue and the tefillin must be placed directly on one's arm and head without anything blocking. The Rosh and Gr"a cite the source from על ידך and בין עיניך implying that it must be directly one one's skin without any chatzitzah.

Our gemara seems to support the position of the Rosh (against the Rashba) because the gemara questions why the tefillin shel rosh isn't a problem while wearing the hat, and responds that the hat sat higher on the head behind the tefillin. Why couldn't the gemara say that the tefillin was placed on top of the hat? It must be that the hat would be a chatzitza for the tefillin just as the tefillin would be a chatzitza for the hat. Perhaps this is why the Shulchan Aruch when relying on the Rashba insists on a "thin" hat, because he understands from the gemara that a thick had similar to the one worn by kohanim would indeed be a chatzitzah. However, it is hard to understand why a thin hat wouldn't be a chatzitza and thick one would, therefore the M.B. explains the problem with the thick hat to be that the tefillin will not be situated in the right place.

Another point that we can derive from this gemara is that kohanim are obligated to wear tefillin shel yad while doing avoda. The shita mikubetzes (6) asks that this seems to contradict a gemara in zevachim which exempts kohanim from the mitzvah of tefillin entirely while doing avoda based on עוסק במצוה פטור מן המצוה. The Shita explains that עוסק במצוה פטור מן המצוה only applies when he would have to put on tefillin at a time where otherwise he would be doing avoda so that the mitzvah would be a bitul of the avoda, but he is required to put on tefillin prior to the avoda and continue wearing them while doing the avoda since there is no contradiction. One of the commentaries in the back (Rashash Toibish) answers based on the Ran in Succah 25a who says that one is exempt from a mitzvah while performing another mitzvah even if he can do both. However, it would seem that since one can put on tefillin prior to beginning the avoda at a time when he hasn't even begun the avoda, even the Ran would require him to do so.

Erchin 2b - Avoiding Mitzvos

The Gemara says that when a child reaches an age that he knows how to wrap himself in clothing, his father is obligated to purchase tzitzis for him. Tosafos points out that the nature of the mitzvah of tzitzis is not an absolute obligation and therefore the father is only obligated to purchase tzitzis for his child when the child has a four cornered garment. But the father is not obligated to purchase a four cornered garment for his child to train him in the mitzvah of tzitzis. Tosafos points out that although the gemara in Menachos 41a considers one who avoids or evades the mitzvah of tzitzis to be deserving of punishment, that is only in those days when they were accustomed to wear four cornered garments, therefore one who went out of their way to avoid it was clearly trying to evade a mitzvah. However, nowadays where most garments are made without having four corners, if one would neglect purchasing a garment that is obligated in tzitzis they aren't deserving of punishment. Tosafos seems to imply that in a time when it was normal to wear four cornered garments, not only should one not avoid the mitzvah for their own garments, they shouldn't even avoid the mitzvah for their child's garments.

The Shita Mi'kubetzes adds that although nowadays it isn't a punishable offense to avoid the mitzvah of tzitzis, it is still proper for one to purchase a four cornered garment to intentionally create an obligation on themselves of tzitzis. The source is from Moshe who yearned to enter Eretz Yisroel to fulfill mitzvos.

In the additions to my sefer Nasiach B'chukecha, I pointed out that there seem to be four levels of avoiding/obligating oneself in mitzvos that they aren't technically obligated in. See Below:

הגדרה בחיוב להכניס עצמו להיות חייב במצות ולפטור את עצמו ממצות:

לענ"ד נראה שיש ד' שלבים לגבי הא דאין לו לאדם לבקש תחבולות לפטור את עצמו מן המצות והחובה להכניס את עצמו לחיוב מצוה. מצינו ענין זה בד' מקומות בש"ס. א. בגמ' קדושין לג ע"א גבי מפני שיבה תקום, קאמר שיכול יעצים עיניו כמו שלא ראהו, וקפריך אטו ברשיעי עסקינן, ומפרש שיכול יעצים עיניו מקמי דלמטי זמן חיובא דכי מטא זמן חיובא הא לא חזי ליה דקאים מקמיה ת"ל תקום ויראת. ופרש"י דילפינן מהכא שיש לך לירא מן היוצר היודע מחשבותיך שאתה מבקש תחבולות להפטר ממצותו. וראיתי בספר דברות משה (קדושין הערה ל"א) שמפרש שזה חמור מהא דאמר מלאך לרבי קטינא דענשינן בעידן ריתחא, שהרי הכא ילפינן מקרא שלא מהני תחבולותיו לפטור את עצמו מן המצוה כלל, והוא מבטל המצוה בידים אלא שנפטר מדין אנוס שלא ידע שעבר מחמת עצימת עינים [ויותר מזה ראיתי בגור אריה (פרשת בהעלותך פרק ט' פסוק א') על פרש"י שם דלא פתח הפרשה בענין הקרבת הפסח משום שהיא גנותן של ישראל שלא הביאו קרבן פסח כל מ' שנה חוץ מזו. התוס' בקדושין לז ע"ב כתבו או שלא היו חייבים עד שנכנסו לארץ או שהיו חייבים אלא שפטורים משום שהיו ערלים, ומ"מ גנות הוא להם שנשארו במדבר מ' שנה מחמת חטא המרגלים. אבל המהר"ל כתב שם וז"ל ולפי דעתי אין צריך, שאף אם הוא פטור מן המצוה או מחמת אונסה או שפטרו, גנאי הוא לו, דסוף סוף לא עשו המצוה כמה שנים שהיו במדבר, שכל מי שהוא פטור מן המצוה מחמת שהוא אונס גנאי הוא לו שלא עשה המצוה, דלא אמרינן בבב"ק כח ע"ב אונס רחמנא פטריה רק לענין פטור מן העונש, אבל מ"מ גנאי הוא לו שלא עשה המצוה והיה לו זכות, וכאן לא היה להם זכות אותו המצוה עכ"ל. הרי סובר דגנאי הוא שלא לקיים מצוה אע"פ שהוא רק מחמת אונס, וכ"ש בנידון דידן שמכניס עצמו למצב כזה ובודאי לאו שפיר עביד שהוא מכניס עצמו למצב שיהיה גנאי לו במה שלא יקיים המצוה. עיין במשך חכמה (פרשת בא י"ג, י') שיש הבדל בין ביטול עשה באונס, לעבירת ל"ת באונס, דבל"ת אין העשיה נחשב לכלום וכאילו לא עשה, אבל בעשה אף כשהיה אנוס מ"מ לא מיחשב כמאן דעביד דסוף סוף לא עשה. ובזה מיישב קושיית התוס' בנדה סא ע"ב אמאי שייך לועג לרש בציצית ולא בכלאים, וכן אמאי קפדינן על בדיקת תפילין ומזוזה יותר מבדיקת ריאה, וכן אמאי קפדינן על שמירת המצה רק למצות לילה הראשונה]. אכן, מדברי הביה"ל (או"ח ס' קכ"ח ס"ב בד"ה או, וכן בס"ד בד"ה אינם) משמע שסובר דקרא ד"ויראת מאלקיך" כללא היא ושייך הכי בכל מקום שמבקש טצדקי לפטור את עצמו ממצות, ואינו דין מיוחד בקימה מפני שיבה, וגם אינו מיוחד למי שמכניס עצמו למצב של אונס. אלא שצ"ע דא"כ אמאי קאמר מלאכא דבעידן ריתחא ענשין, הא יש בזה ביטול מצות "ויראת מאלקיך" וזה חמורא יותר מהא דענשינן בעידן דריתחא, לכן נראה שדרכו של הדברו"מ מדוייק טפי. ב. בגיטין פא ע"א וכן בברכות לה ע"ב אמר רבב"ח אמר ריו"ח משום ר"י בר אילעי בא וראה שלא כדורות הראשונים דורות האחרונים, דורות הראשונים מכניסין פירותיהן דרך טרקסמון כדי לחייבן במעשר, דורות האחרונים מכניסין פירותיהן דרך גגות ודרך קרפיפות כדי לפוטרן מן המעשר. ונראה שגם זה חמור מהא דאמר מלאכא לרבי קטינא, שהרי הכא הם בקשו תחבולות שלא כדרך העולם כדי לפטור את עצמן מן המצות, ונתכוונו לכך שעיקר תכליתם הוא למפטר נפשייהו. ולא דמי לרב קטינא שמסתמא לא נתכוין לפטור את עצמו מן המצוה, רק שניכר לאינשי כן כדהעיר שם בדברו"מ. והנה, בגמ' מנחות סז ע"ב מדמה ענין זה להא דרבי אושעיא שמערים להכניס במוץ כדי להאכיל לבהמתו, וגם למי שאופה פחות מחמשת רבעים ועוד כדי לפטור את עצמו מן החלה. וכל החילוק בגמ' הוא אם גזרו משום בעלי כיסין שהיו מוכרים לעכו"ם ואמרו שאף בשל עכו"ם חייב בתרו"מ, וקאמר דבתרו"מ אע"פ שאפשר להערים להכניסו במוץ כדר"א או להכניסו דרך גגות וקרפיפות לא חששו שיעשה כן משום דהוא מילתא דפרהסיא וזילא ביה מילתא שיאמרו פלוני מערים לפטור את עצמו, ולכן לא נשאר רק עצה למכור לעכו"ם לכך גזרו אף בשל עכו"ם. משא"כ גבי הפרשת חלה שאפשר לאפות פחות מכשיעור בצנעא לא ימכרנו לעכו"ם ומש"ה לא גזרו. מ"מ משמע שבכל ענין שיעשה אפילו כשרק אופה פחות מכשיעור איכא איסורא במה שמערים לפטור את עצמו מן המצוה. ג. במנחות מא ע"א דמלאכא אשכחיה לרב קטינא שהיה לובש בגדים בקייטא ובסתוא שפטורים מציצית, וקאמר ליה קטינא קטינא, סדינא בקייטא וסרבלא בסיתוא, ציצית מה תהא עליה. ומפרש בגמ' דהכי קאמר ליה "טצדקי למפטר נפשך מציצית". ופרש"י וז"ל תבקש תחבולות לפטור עצמך מציצית עכ"ל. ומפרש בדברו"מ הנ"ל דעיקר החשש משום שנראה לאנשי שהיה מבקש תחבולות לפטור את עצמו מציצית דומיא דדורות האחרונים שהכניסו פירותיהן דרך גגות, אע"פ שבאמת זה לא היה כוונתו, ואעפ"כ ענשינן ע"ז בעידן דריתחא. ונלענ"ד שזה מדוייק מאוד בדברי המרדכי (ס' תתקמ"ה) הובא בב"י (או"ח ס' כ"ד) שכתב דמי שיש לו טלית בת ד' כנפות ומבקש עלילות ליפטר נענש, ומשמע מזה דכשאין לו טלית בת ד' כנפות אינו נענש שזה דומה לשלב הד' דמידת חסידות הוא להכניס עצמו למצב של חיוב. ועוד כתב המרדכי וז"ל ודוקא בימיהם שהיו רגילים ללבוש טליתות בת ד' כנפים אבל אנחנו אין דרכנו בבגדי ד' כנפים אפילו בעידן ריתחא לא מיענשי, ומיהא מצוה מן המובחר היא כדאמרינן לא נתאוה משה ליכנס לארץ משום פירותיה אלא כדי לקיים מצות התלויות בה, וה"ה בציצית שגדולה מאוד ומתן שכרה מרובה כדאמר ששקולה כנגד כל המצות. תוס' שאנ"ץ עכ"ל [גם הרא"ש במו"ק (פ"ג ס' פ') כתב כדברי המרדכי דרק כשהיו להם ד' כנפות שייך הא דנענשין מי שלא היתה לו, אבל בזמננו הא דיש לו לחזור אחר ציצית הוא רק מדין משה שביקש ליכנס לארץ לקיים מצות התלויות בה וכ"כ השטמ"ק בערכין ב ע"ב במה שהוסיף על התוס' ד"ה הכל]. ולפמש"כ האגרו"מ אתי שפיר דרב קטינא עצמו לא נתכוין לפטור את עצמו ממצות אלא שמאיזה טעם לא לבש בגד של ד' כנפות. לפיכך כל טענת המלאך לרבי קטינא הוא שניכר לאינשי שמבקש תחבולות לפטור עצמו ממצות ציצית, ולכך כתב המרדכי שזה שייך בזמן שבני אדם רגילין בבגד של ד' כנפות, ולא בזמן הזה [אכן, באמת נחלקו התוס' והמרדכי אם שייך הא דענשין בעידן דריתחא רק כשיש לו ואינו לובשה כמש"כ המרדכי מתחלה דקמיירי דוקא כשיש לו, ומשמע מזה דכשאין לו אף בעידן דריתחא לא ענשינן ליה במה שאינו מחפש אחריו לקנותו. אבל התוס' כתבו דרב קטינא לית ליה בגד המחוייב בציצית, ואעפ"כ קאמר מלאכא דענשינן בעידן דריתחא. עיין בביאורים של הגר"מ בנעט דלדעת המרדכי ניחא דרק שייך למ"ד חובת גברא דקמיירי כשיש לו מש"ה ענשינן בעידן דריתחא אבל אין כופין על קיום מצוה כיון דאינו מחוייב עד שעת לבישה. אבל למ"ד חובת טלית לא שייך הגדרה זו דאין כופין ואעפ"כ ענשינן בעידן דריתחא, דאי כשיש לו מחוייב ועומד וכפינן ליה, ואי כשאין לו הא לא ענשינן. אבל לדעת התוס' קמיירי בדלית ליה ורק משום דחובת גברא ענשינן בעידן דריתחא, אבל אי חובת טלית לא ענשינן כיון שאין החיוב מוטלת אקרקפתא דגברא לא נחשב מי שאין לו כמי שפוטר את עצמו מן המצוה. והשטמ"ק (אות ח') מפרש דלמ"ד חובת טלית נמי ענשינן בעידן דריתחא כשאין לו אלא דשמא היה לו בבית, מש"ה אילו הוי חובת טלית לא הו"ל להמלאך לטעון עליו במה שאינו לובשו]. ד. הבאתי בפנים מתוס' בפסחים קיג ע"ב שמי שאין לו בגד של ד' כנפות יש לו לחזור ולהביא עצמו לידי חיוב, כמו שעשה משה רבינו ע"ה כדאיתא בסוטה יד ע"א שביקש ליכנס לארץ כדי לקיים מצות התלויות בארץ. ונראה דהכא ליכא איסור כלל, שהרי אינו מבקש תחבולות לפטור את עצמו אלא הוא מדת חסידות להכניס עצמו למצב שיהא מחוייב בהמצוה כמו שעשה משרע"ה [וק"ק על האגרו"מ (או"ח ח"ד ס' ד') שהשוה דברי התוס' להא דמלאכא לרב קטינא, דלכאורה לא דק. אמנם באמת יש סתירה בדברי התוס' עצמם שהרי כתבו במנחות דקמיירי בדלית ליה ואעפ"כ ענשינן בעידן דריתחא, וא"כ אמאי כתבו בפסחים שהוא רק בגדר הא דמשה ביקש ליכנס לארץ. ואפשר דדעת התוס' דמי שעומד במצב שהוא פטור אלא שבידו להתחייב עצמו כמו שעשה משה, ולא הכניס את עצמו למצב של חיוב נמי ענשינן בעידן דריתחא, ובזה מיושב גם דברי האגרו"מ שהשוה התוס' בפסחים להא דענשינן בעידן דריתחא וצ"ע]. ויש לעיין בזה, דבשלמא קיום מצות התלויות בארץ שיש בהם תועלת גדולה, שייך חומרא כזה להביא את עצמו לידי חיוב, אבל במצות השמטת כספים או מצות שלוח הקן, או פדיון פטר חמור, או גירושין וכיוצ"ב יש לעיין אם שייך חומרא בזה להביא את עצמו לידי חיוב. ומסתברא שיש לחלק בין מצוה למצוה. ולפמש"כ בשם המרדכי נראה דדוקא במצות גדולות שייך מידת חסידות להכניס עצמו למצב של חיוב כמו מצות התלויות בארץ וכן ציצית ששקולה כנגד כל המצות, אבל בשאר מצות שאין מתן שכרן גלויה לנו, אף ממידת חסידות א"צ להכניס עצמו למצב של חיוב, וצ"ע בזה ואכמ"ל.

Bechoros 57b - Issur to use animals without ma'aser b'heima

The Mishna says that chazal established 3 time periods throughout the year when they required everyone to do the ma'aser b'ehima. The way they imposed this requirement was by considering all animals to be like tevel when the time comes until they separate ma'aser be'heima. When the time comes one is not allowed to eat or sell any of the animals just as they aren't allowed to use grains that are tevel until separating terumah and ma'aser. This is a Rabbinic institution of tevel, which implies that m'doraysa there is no prohibition. Rashi writes explicitly that on a Torah level there is no prohibition at all to use or eat animals before ma'aser b'heima has been separated. Rashi implies that on a Torah level the mitzvah of ma'aser be'heima doesn't impose any restrictions against using the animals.

This is very difficult because by using the animals prior to ma'aser be'heima one can essentially be causing a bitul to the entire mitzvah. Let's say one has only 10 animals or 100 animals - by using any of the animals they are causing a bitul of ma'aser be'heima. How can there be no Torah prohibition to use an animal or animals when it can very likely be causing a bitul of the mitzvah? Furthermore, even when there is no bitul mitzvah, it would seem logical to assume that since there is no time limit by which this mitzvah must get done (one cannot mix animals of two years but they aren't required to do ma'aser be'heima by the end of any given year), shouldn't the mitzvah inherently include an issur to use it until the mitzvah is performed? A similar discussion is raised in the context of using a keli without tevilas keilim. Since the Torah demands that one do tevilas keilim, it should be prohibited to use a keli without doing tevila m'd'oraysa. If not, then one can indefinitely push off this mitzvah without ever being in violation of it. The Biur Halahca (323:7) takes for granted the the prohibition to use a keli prior to immersion in a mikvah is only m'drabonon. It would seem more logical to me that this would be an issur d'oraysa because otherwise one can never be considered to have violated or been me'vatel this mitzvah. Even if we assume like the biur halacha that it is only an issur d'rabonon, here by ma'aser be'heima it is worse since the use of it will often cause a complete inability to do the mitzvah later such as in the case where he has a number divisible by 10 so that any animal used will cause a remainder of 9 on which one can't perform this mitzvah.

It seems to me that Rashi is troubled by this question and is therefore compelled to write - 

אבל קודם לכן מותר דמצוה בעלמא הוא לעשר בהמותיו, דהעשירי קודש מאחר שקרא עליו שם, הבל הרשות בידו לאוכלו בלא מעשר

Rashi understands that the mitzvah is not an obligatory mitzvah, just a מצוה בעלמא. It sounds like he is trying to say that this mitzvah isn't an absolute obligation that one is being me'vatel by using the animal, rather it is a mitzvah to do it but not a violation not to do it.

Bechoros 53a - Uprooting Ma'aser B'heima

The gemara says that although m'doraysa the mitzvah of ma'aser b'heima applies outside of E.Y. and even without a Beis HaMikdash, the Rabbonon uprooted the mitzvah of ma'aser b'heima. At first the gemara thought that they uprooted it because of a gezeira משום יתום, meaning an animal that is technically not chayev in ma'aser b'heima and would end up being put in the coral for ma'aser b'heima and may end up as a korban. The gemara asks that if that were the concern they should have been concerned even when there was a Beis HaMikdash - אי הכי מעיקרא נמי לא. Therefore the gemara concludes that they abolished the mitzvah of ma'aser b'heima due to a gezeira of תקלה, meaning that people would have animals that have kedusha status sitting around and it would lead to using them in forbidden ways. When there was a Beis HaMikdash the ma'aser b'heima would quickly be brought as a korban so that this wasn't a concern, but post beis hamikdash it is a concern.

The Minchas Chinuch (287) explains this gemara by first establishing a concept. We know from the gemara in Yevamos 90 that chazal are empowered to abolish a positive mitzvah in the Torah if it would lead to a violation of some sort as they did with shofar and lulav on shabbos for concern that one would carry it. The achronim ask why didn't they abolish the mitzvah of shofar out of fear that one will make a musical instrument which certainly seems a more likely concern. They answer that a gezeira that one may make an instrument would apply equally to yom tov as it would to shabbos, therefore they would have to completely abolish the mitzvah of blowing shofar on Rosh Hashana. Although they have the power to abolish a mitzvah for a particular time period, they don't have the authority to do so permanently. Therefore, had they based themselves on a reason that applied to Yom Tov also, they couldn't abolish it even on shabbos. They had to find a reason that only applied to shabbos and not Yom Tov.

The gemara at first suggests that they abolished ma'aser b'heima due to the gezeira of a יתום, that one will bring animals that are technically exempt from ma'aser b'heima. However, this gezeira would apply equally with our without a beis ha'mikdash (actually the concern would even be greater when there was a beis hamikdash and one would end up bringing an animal as a korban that is exempt). The Rabbis couldn't make a gezeira that would eradicate entirely the mitzvah of ma'aser b'heima. This is the gemara's question of אי הכי מעיקרא נמי לא. The gemara doesn't just mean to ask that they should have made the gezeira even when the Beis Hamikdash was standing, but rather the gemara means to say that since the gezeira should apply even when the Beis Hamikdash was standing and they couldn't limit their eradication of the mitzvah, they couldn't make this gezeira at all. They were powerless to make a gezeira that would eradicate the mitzvah under all circumstances. Therefore, the gemara is compelled to say that their motivation was תקלה which was a problem that only exists when there is no beis hamikdash but would disappear with the rebuilding of the Beis Hamikdash when people will once again have the ability to sacrifice the ma'aser b'heima as a korban.

A question that can still be asked is why weren't they gozer against doing ma'aser b'heima outside of E.Y. even when there was a beis hamikdash, since R. Akiva held that the animals from outside E.Y. couldn't be brought as a korban - the problem of תקלה should apply as much as when there was no beis hamikdash? Perhaps when there was a beis hamikdash people were more familiar with how to treat kodshim animals even outside of E.Y. and therefore the תקלה concern wasn't as much of a concern.

Bechoros 51b - Pidyon HaBen With the Intent of Receiving the Money Back

The gemara tells that R. Tarfon and R. Chanina would often return the money that he received for pidyon ha'ben (the gemara indicates that there is an advantage to this - קיים זה אף הלכה זו. Rabbeinu Gershom explains that the advantage is to publicize that the halacha allows for the money to be returned. This is similar to what the Rosh explains in Pesachim (Perek 1, 10) that there is an advantage to doing things that are not obviously permitted in order to educate people that it is indeed permitted). The gemara then tells of a situation where someone was hanging around R. Chanina after doing pidyon ha'ben and waiting to get his money back. R. Chanina realized that the person didn't give the money whole heartedly and only gave it because he expected it to come right back. R. Chanina told him that the pidyon ha'ben wasn't effective [Rashi has two versions as to whether it is not effective only if it is returned, or even if it isn't returned. Rabbeinu Gershom and Shulchan Aruch (305:8) assume like the first approach of rashi that so long as it isn't returned, the pidyon ha'ben will be effective. Perhaps after R. Chanina would tell him he can't return the money and the giver would accept that, he would be able to return it].

Tosafos asks that the gemara in Kiddushin says that if one would give pidyon ha'ben to the kohein as a gift with the intent of getting it back, it would be effective. This seems to contradict R. Chanina who held that since the person expected it back, it wouldn't be effective. Tosafos answers that had R. Chanina accepted the money with the intent to return it, as the giver had intended, it would be binding. But, since there is a halacha that a kohein isn't allowed to provide incentive to receive pidyon ha'ben (כהן המסייע בבית הגרנות), R. Chanina didn't receive the money with the intent of returning it. Had both the giver and receiver both intended that it should not be returned, or both intended that it should be returned, the pidyon ha'ben would be effective. The problem in the case of the gemara is that the giver intended to receive it back and the receiver received it without the intent of returning it back. Tosafos question seems to assume that the intent to receive it back should be no worse than the explicit condition to receive it back which is effective. 

However, the Gr"a (shulchan aruch 305) points out that according to the Rosh in Succah, Tosafos question doesn't even begin. The Rosh in Succah (3,30) explains that a מתנה על מנת להחזיר is a very specific and rigid agreement that requires a kinyan on the return end as well. It isn't merely an informal assumption that the money will be given back. Therefore, the case of R. Chanina doesn't meet the requirements of a מתנה על מנת להחזיר. When the giver intends to give it for only a short amount of time and then receive it back, it is like a מתנה לזמן, a gift with an expiration date which doesn't qualify as a matana at all and wouldn't work for pidyon ha'ben.

Bechoros 49a - Pidyon Ha'Ben After Death

The Mishna requires one to do pidyon ha'ben to a child who lived passed day 30, but then died. Tosafos questions whether one should make a bracha of shehechiyanu when performing pidyon ha'ben on a dead child. The Birkas Shmuel (Kiddushin #18) points out that the only rationale that Tosafos has not to say Shehechiyanu is that there is pain associated with it due to the child's death, but the implication is that the mitzvah is in full force as if the child was still alive and therefore shehechiyanu may be appropriate. The difficulty with this is that the Rivash explains in a teshuva (131) that the language for the bracha on pidyon ha'ben is "על פדיון הבן" rather than "לפדות". He explains that this fits well with the Rambam (Brachos 11:12) who says that anytime the mitzvah is done for someone else i.e. separating teruma one someone else's grain, or hanging a mezuza in someone else's house, the bracha should be על. Therefore, when one performs pidyon ha'ben for himself, the bracha should be לפדות, but when he performs it for his son, since it is primarily the son's obligation that the Torah requires the father to perfrom, the bracha should be על. The Birkas shmuel asks that the Rambam (11:10) says that shehechiyanu is made when one is doing their mitzvah, not when one is doing the mitzvah of someone else. If we regard pidyon ha'ben as the son's mitzvah, not the father's, hence the bracha is made using the term על, there shouldn't be any shehechiyanu. From Tosafos we find that not only is shehechiyanu made on a standard pidyon ha'ben that the father does for the son, but even after the son dies, the bracha of shehechiyanu is made. It would seem that after the son has died we can no longer say the father is performing the mitzvah for his son, because there is no obligation on a deceased person to do any mitzvah. The fact that the father performs the mitzvah after the son's death and makes the bracha of shehechiyanu, implies that the obligation of the father to redeem his son is primarily the father's own obligation, not merely something the Torah requires him to do for his son. The Birkas Shmuel points out that this directly contradicts the Rivash.

The Birkash Shmuel explains that the obligation for a father to do pidyon ha'ben after his son has died is not to fulfill a mitzvah obligation, rather the debt that was created by the mitzvah before the son had died must still be paid. It is a monetary obligation rather than a mitzvah obligation. However, he suggests that although there is no longer a mitzvah obligation on the father since the son has died (and we are assuming like the Rivash that the primary mitzvah is on the son), there is still a kiyum mitzvah, a fulfillment of a mitzvah that is achieved by the father doing pidyon ha'ben on the deceased son. Now, the bracha of shehechiyanu is different than the bracha of על פדיון הבן in that the bracha of shehechiyanu is on the joy one receives from the opportunity to fulfill a mitzvah. Even on a kiyum mitzvah the bracha of shehechiyanu is appropriate. But a birchas ha'mitzvah is a bracha on the chiyuv, not on the kiyum, as the text of the bracha indicates וצוונו על פדיון הבן. Since the primary chiyuv is on the son, just that until he is 13 the Torah places that obligation on the father to fulfill his son's mitzvah, the language of the bracha is על פדיון הבן since the primary obligation is on the son, not the father. But regarding the shehechiyanu which is on the kiyum ha'mitzvah, the father is certainly fulfilling a mitzvah and can therefore make shehechiyanu. Following this approach it should follow that when a father does pidyon ha'ben after the son had died, since there is a monetary obligation to pay a debt but no longer a mitzvah obligation since the son is dead, there shouldn't be any birchas ha'mitzvah at all. The Birkas Shmuel points out that someone asked him this question, but he was pushed off the question saying that since at some point there was an obligation, even though now it is only a kiyum, the bracha may still be made. But for shehechiyanu, if it were made for a chiyuv mitzvah, it would not be made at all when there is no chiyuv. The fact that Tosafos says it is made after the son's death indicates that it is made for a kiyum mitzvah even when there is no chiyuv.

See here for the Birkas Shmuel

Bechoros 46a - Who is the halachic mother?

The issue of surrogacy and determining whether parenthood depends on genetics or on birth is very complicated in halacha and difficult to prove. See here for an article by Rav Zalman Nechemia Goldberg Shlit"a where he proves from various sources that the mother who gave birth to a child is considered the mother in halacha, not the mother who donated the genetic material. This is not the forum to weigh in on such a major topic but one of the cases in our mishna opens it up for discussion. 

Regarding fatherhood, it would seem that it is determined by the one who contributed the semen, since that is the only active role the father takes in producing the child. However, we find that if a man would have relations with a non-jew, the child born would not be halachically related to the father. Rashi writes that if a woman converts while pregnant, the child wouldn't inherit from the biological father since conception happened with a mother who was a goy, the Torah no longer connects the semen to the father - דזרע מצרי רחמנא אפרקריה דכתיב וזרמת סוסים זרמתם. Tosafos agrees, but comments that if the mother converts while pregnant, the child anyway isn't related to the father because the child is considered a convert and גר שנתגייר כקטן שנולד דמי breaks his relationship with his biological family. Therefore, it would seem that in a situation where the bio mother and the surrogate mother are both jewish, we would consider the father to be the father. But, if either one is not Jewish, whether the father is considered the father would seem to depend on who is the mother. If the bio mother is considered the mother, perhaps we would consider the bio father the father even though his semen eventually was placed in the uterus of a non-jewish woman. But, if we consider the surrogate mother to be the mother, the biological fathers connection would likely be broken as well.

It seems that the answer to who is the mother may also lie in this case. When a woman converts while pregnant, we consider the child born after conversion to be a bechor regarding pidyon ha'ben - he is the פטר רחם. It would seem that before we entertain the ability of the child to be considered the פטר רחם of this woman, we must first consider him the child of this woman. The gemara says in Yevamos 78a that when a woman converts while pregnant, the conversion works for the child also and he is considered a convert (the womb isn't a chatzitza for the tevilla). Since we would apply כקטן שנולד דמי at the time of conversion, we would not consider the woman pregnant with her own child (even if conception would normally determine motherhood), yet when the child is born we consider him to be a פטר רחם. It would seem that birth determines the relationship between the mother and child because otherwise we shouldn't consider this child to be the פטר רחם. One can disagree with this logic by underlying the assumption. Perhaps motherhood is not a prerequisite for this child to be a פטר רחם. Therefore, even though we wouldn't consider him to be the child of this mother, he would still have kedushas bechor for pidyon ha'ben.

R. Zalman Nechemia cites an excellent proof that it is dependent on birth from the gemara in Yevamos 97b that says when a woman converts while pregnant with twins, the two brothers are considered brothers for the prohibition of אשת אח (if one would have relations with the others wife after he dies). Even though conception would not consider them brothers because they went through a conversion in the process, the halacha still considers them to be brothers because they are born from the same womb. Just as the relationship between the two brothers is determined at birth, the relationship to the mother should also be determined at birth. According to this approach it is not gestation or incubation of the surrogate mother that would determine her to be the mother in halacha, because the gemara indicates that the same halacha would be true if the mother converted well into her ninth month, a day prior to the birth of the child. Rather, it is the actual birth that would determine the familial relationships.

Rav Zalman Nechemia points out that the gemara in Chulin 70a would seem to imply the exact opposite. The gemara discusses a case where an animal gives birth to a bechor directly into the uterus of another, the second animal then gives birth to this bechor and the gemara wants to know whether a child that doesn't belong to it can exempt it from bechor (in the future). The implication of the gemara is that the child doesn't belong to the second mother, even though it also gave birth to it. However, Rav Zalman Nechemia rejects this proof. He points out that since the first animal also gave birth to it, the child already has a mother, therefore the second mother isn't considered a mother. But if the surrogate mother is the first to give birth to the child (as a viable human being or animal), the surrogate mother would be considered the mother.
According to Rav Zalman Nechemia Goldberg the proof from Yevamos 97b is sufficient evidence that the family relationship is established at birth, therefore the surrogate mother is considered the mother. It would therefore follow that if he surrogate mother were a non-jew, even if the genetic mother was jewish, the child would not be jewish.
However, my uncle, Rav Shabtai Rappaport has a very unique (and complex) approach to this issue that I found in an article online - see here. He considers the gemara in Yevamos 97 evidence for determining the family relationships in regard to עריות but not for the purpose of determining status as a Jew. He suggests that the fact that the gemara in Yevamos 78 considers the child of a pregnant convert to be going through his own conversion, implies that the child's religious affiliation is determined at conception by the genetic mother. Since the genetic mother is a non-jew at the time of conception, the child would not be a Jew unless we consider him to have undergone his own conversion. Even if the mother converts while pregnant and the child is born to a Jewish mother, this would not transform him into a Jew since his genetic material wasn't Jewish at the moment of conception. In the case of surrogacy it would then follow that the surrogate mother is considered the mother, but the genetic mother determines whether the child is a Jew. When the surrogate mother is a non-jew and the genetic mother is a Jew, the child will be Jewish but his "mother" will be the non-jewish woman.
The approach of Rav Shabbtai Rappaport is novel, but it is odd to separate between the question of who is the mother and the one who passes on the Jewish "gene". To me it seems that the proof from the pregnant mother converting doesn't force us to say that Jewishness is passed on by the genetic mother. Perhaps if the mother were able to convert without also converting the fetus she is carrying, the child would still become Jewish upon birth from a Jewish mother. But, since the conversion of the mother automatically works on the child that she is carrying, the child is considered Jewish due to conversion rather than a result of being born to a Jewish mother.