Pesachim 120 - Bracha on Ma'aseh Mitzvah before Kiyum HaMitzvah

In the sugya of mitzvos tzrichos kavana 115a, which speaks about a case where one is using marror for both karpas and marror, there is a machlokes Rav Huna and Rav Chisda whether you make the bracha of על אכילת מרור by the eating of marror, or earlier by the eating of karpas. Tosafos explains that both Rav Huna and Rav Chisda agree to Reish Lakish 114b that mitzvos require kavana and he will not be yotzei the mitzvah of marror with the eating of marror by karpas. Yet, Rav Chisda holds לאחר שמילא כריסו הימנו חוזר ומברך עליה!, it doesn't make sense to eat marror without a bracha of על אכילת מרור and only make the bracha later. Therefore, he should make the bracha earlier by the eating of karpas. Tosafos questions how one is able to make a birchas hamitzvah on the eating of karpas if he isn't going to be yotzei the mitzvah of marror until later. Tosafos writes that the bracha made earlier works since he is going to be eating a little marror at the time of the bracha, even though he isn't going to be yotzei until later. Tosafos even implies that he doesn't need to eat a kezayis at the time of the bracha, so long as he eats a kezayis later on. It seems from Tosafos that one can make a bracha on a ma'aseh mitzvah, even though the kiyum hamitzvah will not be until later.

Perhaps this approach can be supported from the mitzvah of sefiras ha'omer, according to those who hold that there are 49 components to be yotzei the one big mitzvah of sefira. We make a bracha each night on the ma'aseh hamitzvah even though the kiyum is pending until the last night. However, by sefiras ha'omer each night one is at least doing a component of the mitzvah that will ultimately make up the greater mitzvah of sefira. But in the case of Tosafos, the marror that is being eaten as karpas on which he is making the bracha ultimately contributes nothing to the fulfillment of the mitzvah.

Tosafos draws a parallel from shofar where we make a bracha on the tekios d'meyushav, even though the mitzvah d'oraysa is only fulfilled by the teki'os d'me'umad. The Chazon Ish (O.C. 124) points out that this is also a difficult comparison because by shofar there is at least  a mitzvah d'rabonon being done with the teki'os d'me'yushav so that it is not a bracha l'vatala, but by marror there is no mitzvah at all being done with the marror of karpas. What is the comparison? It seems that Tosafos is not focused on the bracha being l'vatala. They take for granted (even though it seems difficult) that since he is doing the ma'aseh mitzvah it wouldn't constitute a bracha l'vatala. The concern of Tosafos is how does the bracha done earlier work for the mitzvah performed later, which they prove from shofar that just like the brachos on tekios d'me'yushav works for the later te'kios d'meumad, so too the bracha on karpas works for the eating of marror later.

There is a machlokes Rashbam 119b and Tosafos 120a whether the primary mitzvah of matzah is fulfilled with the first eating of matzah on which we make a bracha or on the matzah of afikomen. Rashbam understands that it is the matzah of afikomen and therefore draws a parallel from Rav Chisda that a bracha could be made on the ma'aseh mitzvah that is done earlier, and work for the kiyum hamitzvah that will only be later. Tosafos agrees that according to the Rashbam it would be a good comparison, but holds that the primary mitzvah of matzah is fulfilled with the matzah eating l'tei'avon at the beginning of the meal.

Pesachim 113b - Defining the violation to hate "in your heart"

The gemara says that when someone sees another do an aveira, even if there aren't two witnesses so you can't testify on him in a court, you are allowed to hate him. The gemara proves this point from the pasuk that describes חמור שונאך רובץ תחת משאו - the donkey of your enemy crouched under its load. What type of enemy is the Torah speaking about? The gemara says that it can't be someon that you hate for no good reason because that would be a violation of לא תשנא את אחיך בלבבך, therefore it must be speaking about an enemy that you hate because you saw him doing an aveira.

The gemara implies that the ONLY way that one can have a Jewish enemy, yet not be in violation of לא תשנא את אחיך בלבבך would be when you see him do an aveira and are therefore allowed to hate him. There is a big machlokes in the Rishonim regarding the parameters of לא תשנא and why the Torah specifies בלבבך - in your heart. Rabbeinu Yona (sha'arei teshuva 3:39) and the Ramban both say that all hatred is included. The only reason that the Torah writes בלבבך is because that is more common, but the issur would be violated even if he expressed his hatred. However, the Rambam (Hil. Deios 6:10) writes that the only violation is when one hides the hatred in his heart, but when one expresses the hatred they would not be in violation. The Rambam seems to be contradicted by the gemara because the gemara indicates that all hatred would be included. According to the Rambam the gemara should have said that there can be an enemy who you hate for no good reason, but as long as you tell him that you hate him you would avoid the violation of לא תשנא. How will the Rambam learn this gemara?

I think that the Rambam would say that the context of the gemara is defining the term שונאך of the Torah. The Torah is speaking in a context where you would be going to help him unload his donkey. This would be a clear display of love. The very act of helping him would hide the animosity and hatred that you feel for him. Therefore, it could not be speaking about someone you hate for no reason because that would violate לא תשנא את אחיך בלבבך, since the actions of helping him give him the impression that you don't hate him.

Pesachim 105b - Drinking from Kos Shel Bracha

One of the eight points that the gemara draws from the braisa is that המברך צריך שיטעום, when one uses a kos shel bracha, they need to actually drink from the kos shel bracha. I gave a shiur recently on the minhag in many shuls to say birchas hamazon on a kos after shalosh seudos, daven ma'ariv and then return to use the same cup for birchas hamazon. According to the simple reading of the gemara 102b and the Shulchan Aruch 299:4, this should be a violation of אין עושין מצות חבילות חבילות. See HERE for a halachic justification regarding that issue.

Another issue with the predominant custom is how one fulfills the requirement of המברך צריך שיטעום on the kos of birchas hamazon. This would be an issue even if one were to use separate cups for Birchas Hamazon and Havdala, since the drinking is typically not done until after ma'ariv. The Biur Halacha (299:4 d.h. mevareich) explains that as long as one generally makes birchas hamazon on a kos, they are able to drink from the kos of birchas hamazon even before havdala. The M.B. cites the Chayei Adam who holds that even if one typically doesn't use a kos for birchas hamazon, they can still drink immediately following bentching, before making havdala, so long as it isn't definitely night - ספק חשכה. However, in most situations people are not makpid to use a kos for birchas hamazon, and shalosh seudos ends at צאת הכוכבים, so drinking from the kos of birchas hamazon at that point would be a problem. The Biur Halacha writes that in a case where one cannot drink (either because he only has one kos, or because he can't drink before havdala), the Bach holds that one should make havdala on a kos of wine immediately, prior to davening ma'ariv, then drink from both the cup of havdala and the cup of birchas hamazon. Pausing to daven ma'ariv would be too long of a break between the birchas hamazon and the drinking from the cup. This is also clearly the opinion of the shulchan aruch ha'rav. But, the Biur Halacha quotes the Derech HaChayim who says that it is fine to daven ma'ariv in between, which is the minhag ha'olam.

It seems to me that the reservation of the Biur Halacha is correct, and davening ma'ariv between the birchas hamazon and havdala is a problem because the drinking after havdala would not be effective for the kos of birchas hamazon, and would undermine the entire advantage of being bentching on a kos. The Rashbam explains that from the fact that we don't tell the person who needs to eat on Motzei Shabbos and make Havdala, to first make havdala, then eat, then bentch and drink the kos, implies המברך צריך שיטעום. But why is this a violation of המברך צריך שיטעום, he will drink from this very kos after bentching and that would qualify as the the drinking for both the havdala and the birchas hamazon? Clearly, the Rashbam holds that eating a meal between havdala and birchas hamazon would be too much of a hefsek and not allow the drinking to go back on the havdala. Just as the meal would constitute a hefsek, and therefore not allow the drinking afterward to qualify as המברך צריך שיטעום, so too the davening would constitute a hefsek as the shulchan aruch ha'graz holds, not like the minhag ha'olam and not like the derech hachaim.

Pesachim 85a - Breaking Bones of Korban Pesach to Eat Marrow

The gemara cites a machlokes between R. Yochanan and Reish Lakish whether the prohibition to break the bones of the korban pesach only apply to an area of the bone which has a kezayis of eatable meat, or so long as the bone has on it a kezayis of meat there is an issur to break the bone at any point. The gemara says that even according to Reish Lakish who holds that the issur only applies to a spot of the bone that has a kezayis of meat, it doesn't matter whether the eatable part is on the outside of the bone in the form of meat, or on the inside in the form of marrow. Either way, there is a prohibition to break the bones. The gemara clearly maintains that there is an issur to break the bones when there is marrow inside (even if there is no meat on the outside).

The gemara cites a braisa to support this point. The Braisa points out that there is a contradiction between two pesukim that must be reconciled. On one hand the Torah says ואכלו את הבשר בלילה הזה implying that all the eatable parts of the korban pesach must be eaten, including the marrow. On the other hand the pasuk says ועצם לא תשברו בו implying that one may not break the bones, even to get to the marrow. We are forced to limit one of these two pesukim. Either we must limit the mitzvah of eating the korban pesach to the meat on the outside and not the marrow within, in order to uphold the blanket prohibition to break the bones. Or we must limit the issur to break the bones to include only marrow-less bones, but bones in which there is marrow one would be entitled to break so that they can get to the marrow. The braisa continues that the latter approach is plausible since we find that there is a concept of עשה דוחה לא תעשה, as if the mitzvah of eating korban pesach would push off the prohibition to break the bones. However, the braisa concludes that since we have an extra pasuk by pesach sheini warning against the breaking of the bones, the Torah is indicating that the bones cannot be broken under any circumstances, even to get to the marrow inside.

Tosafos asks, why would we need a special pasuk to teach not to break the bones. The concept of עשה דוחה לא תעשה shouldn't really work here since it is not בעידנא, meaning that the לא תעשה of breaking the bones is violated prior to the performance of the aseh. In such a situation we do not allow the aseh to push off the lo ta'aseh. Why would we need an extra pasuk by pesach sheini? Furthermore, the paradox is not absolute. One can fulfill the mitzvah of eating the marrow without breaking the bones. Since the paradox can be reconciled by using a coal to burn through the bone rather than breaking it, it is considered אפשר לקיים שניהם so we don't allow the aseh to push off the lo ta'aseh. In short, why does the braisa claim to warrant an extra pasuk based on the rule of עשה דוחה ל"ת. Since it is not בעידנא and it is אפשר לקיים שניהם, there are two reasons for us not to apply the concept of עשה דוחה לא תעשה to this case? Tosafos only answers the second question by saying that if the problem of the coal is because it will burn through some of the marrow and be a violation of הפסד קדשים, it is not a possibility and therefore is considered אי אפשר לקיים שניהם. However, the first question of Tosafos still remains?

I would suggest that the braisa never meant to apply the technical concept of עשה דוחה לא תעשה. The braisa is actually suggesting that due to the inherent contradiction between the mitzvah of eating the meat and marrow, and the issur of breaking the bones, we should limit the issur to only apply to bones that have no marrow. This is not applying the concept of עשה דוחה לא תעשה because that concept does not limit the lo ta'seh, rather it overrides it. The braisa is only saying that conceptually one should not find it strange that the mitzvah of eating the korban pesach would prevail over the issur to break the bones, forcing us to limit the issur, because we always find that an aseh pushes off a lo ta'aseh. The braisa doesn't met to apply the technical concept, just draw a conceptual parallel to justify limiting the issur to bones with no marrow.

Rashi also asks the second question of Tosafos. Why does the gemara consider there to be an absolute contradiction between the mitzvah to eat the korban pesach and the issur to break the bones, they can both be fulfilled by using a coal to burn through the bone? Rashi answers - דלא מצריך ליה קרא מילתא דאתי בה לידי תקלה דלמא פקע, the torah wouldn't require doing something that can cause the breaking of the bone. At first glance, Rashi is very difficult to understand. The gemara on 84b was very clear that this concern of דלמא פקע is only Rabbinic in nature, but on a Torah level using a coal is a good option to access the marrow without violation. How can Rashi say that the Torah itself rejects this option, since the entire concern is only Rabbinic? I would suggest that Rashi is not referring to the Rabbinic prohibition of using a coal to burn through out of concern that it will cause a crack. Even if the Rabbonon never created such a prohibition, Rashi would make sense. Rashi is saying that the Torah would not include the marrow in the mitzvah and obligation to eat korban pesach if there were a significant chance that by doing the mitzvah one would be in violation of an issur. Even if it were permissible m'dorayas and even m'drabonon to use a coal to burn through the bone, since there is a concern that it will break the bone, albeit a small concern, the Torah would not require it to be done to fulfill the mitzvah. In other words, Rashi is saying that we never find that the Torah would obligate a mitzvah at the risk of the violation of an issur. This is a fascinating yesod!

Pesachim 70a - Eating the Korban Pesach While Full

The Mishna 69b explains that a korban chagiga would accompany the korban pesach when there were too many people counted on the the korban pesach. The gemara explains that the korban chagiga was not an obligation and the function of it was only to make sure that the korban pesach was eaten על השובע. Why is it necessary to eat the korban pesach על השובע? Tosafos cites from the Yerushalmi that it is a din D'rabonon because when one is too hungry they would come to break the bones. If people are too hungry, then when they are hastily eating the meat around the bones they will be too rough and break the bones. By implementing a korban chagiga to ensure that everyone would not be so hungry when they came to eat the korban pesach, there would not be a concern that they will accidentally break the bones. Tosafos later on 120a adds an additional peshat - שלא יצא משולחן רבו רעב. It is degrading to walk away from eating a korban and still be hungry. Therefore, we want to make sure that he eats enough before the korban pesach so that he can walk away from the korban pesach satiated. The difference between these two approaches is that according to the first approach we want to make sure that he begins eating the korban pesach על השובע so he won't break the bones, whereas according to the second approach we want him to be full when he finishes the korban pesach. According to the first approach it is difficult to understand why we would only bring a korban chagiga when there are many people counted on the korban pesach, but if there would be only a few, one would not need a korban chagiga. Shouldn't we always encourage one to have many people on the korban pesach so that we can force bringing a korban chagiga to ensure that when they begin eating the korban pesach they won't be hungry? It seems that ideally one should have a large number on the korban pesach so that they are forced to bring a korban chagiga, so that when they begin the korban pesach they are already somewhat satiated and won't come to break the bones.

Rashi seems to have a third approach in understanding על השובע. When one eats something when they are starving, they don't enjoy the taste of it. Only after the severe hunger subsides does one begin to enjoy what he is eating. We insist on a korban chagiga so that one will not be so hungry when they begin eating the korban pesach. By doing this they will enjoy the korban pesach more which is a kavod and chashivus for the korban pesach. According to this approach also it would seem that it is ideal to have more people counted on the korban pesach and force the bringing of a korban chagiga so that when they begin the korban pesach they are already full.

Pesachim 64a - Reading Hallel

The mishna says that they would read Hallel by each of the three groups as they brought their korban pesach. Tosafos cites the Tosefta that it was the Levi'im who would read the Hallel, not everyone. Tosafos asks that if it was the Levi'im who would be reading the Hallel, it should have a status of שירה and would be a violation of the rule אין אומרים שירה אלא על היין. Tosafos answers that the halacha of אין אומרים שירה אלא על היין is a halacha in being "makriv" the korban. The shira which complimented the burning of the korban on the mizbeiach was done specifically at the time of the nisuch ha'yayin. Here the Hallel is not being said at the time of the hakrava, rather we are talking about Hallel at the time of shechita. On this type of shira there is no requirement of אין אומרים שירה אלא על היין.

The Brisker Rav (Hil. Chanuka) cites the Rambam who says that Hallel is a תקנה מדברי סופרים, whereas the Magid Mishna writes that it was a תקנת נביאים which is the language of the gemara as well. The Brisker Rav explains that there are 2 dinim in Hallel. There is a Hallel of שירה such as the Hallel said at the time of the eating of the korban pesach - כליל התקדש חג, as we see in the gemara 95b. There is also the Hallel which is a קריאה such as the Hallel done on every Yom Tov in shul. Hallel as a שירה is a  תקנת נביאים but Hallel as a קריאה is מדברי סופרים. Regarding the Bracha on Hallel, we only make a bracha (מעיקר הדין) on the "full" Hallel because only the full Hallel has status of Hallel. But when Hallel is being said as a shira, there is no specific amount that must be said, therefore they could make a bracha on it even if it wasn't completed. The Brisker Rav explains that the Hallel at the time of shechting the korban pesach is a din in shira, therefore it wasn't necessary for the 3rd group to complete it as the Mishna explains. The Brisker Rav concludes by citing a Tosafos HaRosh that there are 3 times where we say Hallel without wine, which are exceptions to the rule of אין אומרים שירה אלא על היין. The 3 times are: 1. Hallel of shechitas HaPesach. 2. Hallel by eating the Pesach. 3. Hallel by war. Why don't they also count every Hallel of Yom Tov which are also exceptions? The Brisker Rav explains that only when the Hallel is being said as a shira do we regard it as an exception when it is done without wine. When the Hallel is being said as a קריאה, of course it is said without wine.

Based on this, Tosafos would also categorize Hallel of shechitas HaPesach as a שירה not a קריאה, yet since it is not done at the time of hakrava, we don't require it to be done on wine.

Pesachim 63a - Shechting Korban Pesach With Chometz

The Rambam (Hil. Korban Pesach 1:5) writes that if one shechts, sprinkles the blood or burns the eimurin of a korban pesach while one of them has chometz or one of the chabura has chometz, all those playing an active role in the korban (שוחט, זורק ומקטיר) are in violation. The implication of the Rambam is that the members of the chabura, even the one who has chometz is not in violation since they are not doing any active part of being מקריב the korban. Tosafos writes that the one who has chometz is not in violation. However, Tosafos gives two explanations why the member of the chabura that has the chometz is not in violation: 1. The Torah says לא תשחט implying one who does an avodah. 2. It is a לאו שאין בו מעשה so there can't be malkus. The Minchas Chinuch (Mitzvah 89) points out that according to the first answer of Tosafos it seems that the בעל החמץ is not in violation of anything, whereas the second answer of Tosafos implies that he is in violation, just that he doesn't receive malkus for a la'av sh'ein bo ma'aseh. Rashi seems to disagree with both the Rambam and Tosafos. Rashi on the mishna writes that if one of them has chometz, they are ALL in violation, implying that not only is the בעל החמץ in violation, but all the passive members of the chabura are also in violation.

Another issue is whether the violation of this לאו invalidates the Korban Pesach. Tosafos writes that the Pesach is kasher since there is no repetition to indicate that the violation of this would cause passul the korban. The Rambam also writes that the korban is kasher [In the pirush hamishna he also writes - ולא יפסיד הזבח]. The kesef mishna points out that this is the implication of the mishna since it only says that you would violate a לא תעשה and doesn't mention the korban.

There is a Mishna L'melech that discusses whether the זורק or מקטיר would be in violation of a korban pesach that has already become passul. Is the violation of לא תשחט על חמץ only on a kasher korban pesach, or even on a passul one? The Mishna L'melech proves from a Yerushalmi that it would not apply to a passul korban pesach. In the Yerushalmi, R. Shmuel says that from the fact that the issur even applies to the zoreik, it must be that the pesach is kasher. Meaning, if the korban pesach that is shechted while one has chometz is passul, the korban would have already become passul by the shechita so that the zoreik would not be in violation. The fact that the zoreik can also be in violation implies that the korban is not invalidated by being shechted with someone having chometz. The entire approach of R. Shmuel in the Yerushalmi assumes that on a passul korban pesach one cannot be in violation of this prohibition.

The Tzlach suggests a similar lomdus to the mishna l'melech in his understanding of Rashi, from which he tries to prove that the korban would be invalidated by being shechted while someone has chometz. Rav Papa says that the מקטיר will also be in violation of this issur. Rashi explains that we are speaking about a circumstance where none of the בני חבורה had chometz so that there was no violation until now, the one who burns the korban on the mizbeiach will be in violation if he has chometz. Why does Rashi need to say that we are speaking where the בני חבורה don't have chometz? It must be that Rashi assumes that if the בני חבורה had chometz so that the issur was already violated by the shechita, the korban would be פסול, therefore the מקטיר would not be in violation. Rashi assumes like the conclusion of the mishna l'melech that on a passul korban, one cannot be in violation and therefore needs to make the case where the korban was not invalidated. The Tzlach later rejects this diyuk, but according to this diyuk, Rashi would hold that the korban becomes invalidate if any of the avoda is done while someone in the chabura or one of the makrivim have chometz.

Pesachim 58b - Korbanos In Between Morning and Afternoon Tamid

The gemara cites Rava who learns from the pasuk of העולה that the korban Tamid has to be the first one brought in the day, and learns from והקטיר עליה חלבי השלמים that nothing can come after the evening korban Tamid, rather עליה השלם כל הקרבנות כולן. Tosafos asks that there is another source in perek ha'tadir that the gemara learns from מלבד עולת הבוקר אשר לעולת התמיד, implying that the Tamid is first. Why do we need both pesukim? Tosafos rejects the possibility that repeating it is to tell you it is me'akeiv, meaning that a korban would be invalid if brought afterward, because the gemara says explicitly that it is not l'ikuva. In Tosafos second answer they say that the pasuk in our gemara focuses on the burning of אימורין on the mizbeiach prior to the Tamid, whereas the pasuk in hatadir is to tell you that the shechita of the Tamid is first. Tosafos also points out that the gemara in Eiruvin says that a korban shelamim brought prior to the opening of the doors of the heichal is invalid, proves that shechting before the tamid won't invalidate, because if it were then we wouldn't need a pasuk to invalidate prior to the opening of the doors.

Tosafos cites the gemara that says that a korban brought prior to the morning tamid wouldn't become passul, but isn't clear about whether a korban that is brought after the korban tamid would become passul. Tosafos in menachos writes that it wouldn't become passul if brought after the evening tamid. Tosafos on thid daf implies that as well because the Tosefta says that a korban brought prior to the morning tamid or after the evening one would become passul, to which Tosafos writes that it is only m'drabonon, implying that they are the same and that m'doraysa neither would be passul. Rashi d.h. kach, writes that nedarim and nedavos brought after the evening Tamid would become passul. See Mishneh L'melech (1:3 of Hil. Temidin U'musafin who is ma'arich very much on these issues).

The Mishna L'melech points out that the Rambam seems to hold like Tosafos because the Rambam (1:3) writes it in the form of an issur, but makes not mention of korbanos being invalid if brought before the morning tamid or after the evening one.

The Rambam writes - לפי שאסור להקריב קרבן כלל קודם תמיד של שחר, ולא שוחטין קרבן אחר תמיד של בין הערבים חוץ מקרבן פסח לבדו שאי אפשר שיקריבו כל ישראל פסחיהן בשתי שעות

The Rambam writes that the only korban brought after the evening Tamid was the korban pesach and the rationale he offers is that if you were to bring the korban pesach prior to the tamid, it would need to be brought between 12:30pm and 2:30pm and two hours isn't sufficient time for the korban pesach. Therefore, it is brought after the Tamid. The Lechem Mishna points out that this rationale is difficult because if the problem were merely the limitation of 2 hours they should have allowed it to be brought either before or after the Tamid. Furthermore, the gemara gives another rationale, since it says by Pesach both בערב and בין הערבים, it implies that it is pushed to later.

Another difficulty with the Rambam is pointed out by the Mishna l'melech at the end of his esssay. Why does the Rambam say that no korban is "brought" prior to the morning Tamid and no korban is "shechted" after the evening one. Tosafos holds that by the morning Tamid where there are two pesukim, one indicates the issur to be makriv (הקטרת אימורין) and the other indicates the issur to shecht, implying that the pasuk cited in our gemara for not sacrificing after the Tamid would be consistent with the context and forbid הקטרה after the evening Tamid. This seems to be the opposite of the Rambam! The Mishna L'melech explains that technically there is no issur to shecht before or after the Tamid, the entire issur is only on being makriv. The reason is that shechita is not regarded as an Avoda and therefore there are no rules limiting it. In the morning one could shecht prior to the morning korban tamid. But, in the evening since if one were to schecht they would be unable to be burn the korban properly or sprinkle the blood, it is assur to even shecht because the are causing the korban to be wasted. Therefore, the Rambam is very meduyak that before the morning Tamid it is only forbidden to be makriv, whereas after the even Tamid it is even forbidden to shecht.

Pesachim 57a - Pei'ah on Vegetables

In the Mishna we find that the people of Yerichos left Peiah on vegetables, and the chachamim protested. The gemara explains that there was a legitimate halachic argument between them. The issue was whether the leaves of turnips qualify as מכניסו לקיום which is one of the conditions to be chayev in peiah. The people of Yericho held that since it is able to be stored together with the turnip bulbs, it qualifies as מכניסו לקיום and is obligated in Peiah, whereas the Chachamim held that this does not qualify as מכניסו לקיום and is exempt from Peiah. Therefore, according to the Chachamim, the people of Yericho who were treating the turnips like Peiah and not separating Teruma and Maaser were causing the poor people to violate the prohibition of eating tevel, that is why they protested.

Rashi on the Mishna explains that the problem with what the people of Yericho were doing is that they were considering it Peiah when it reality it wasn't and causing the poor to eat tevel, as we explained. According to this approach, there is room for Tosafos question - Even if Peiah is not technically binding, it should be considered hefker which is also exempt from ma'aser, so it shouldn't be a problem of eating tevel (Tosafos answers that since they only allowed the poor to eat and not the rich, it didn't qualify as hefker). However, in explaining the story of בן בוהיין, Rashi explains it very differently. Rashi implies that the leaving of Peiah on vegetables was effective in exempting it from ma'aser because it assumes a status of hefker and hefker is exempt from ma'aser. The problem is not that they poor would be eating tevel, rather the problem was that by doing a ha'arama to make it hefker and exempt from ma'aser is not proper. The Maharsha points out that Rashi in the Mishna is not the same peshat as he offer in the story of בן בוהיין, whereas Tosafos understood the case of בן בוהיין to be exactly the way Rashi explained in the Mishna.

Why does Rashi explain the case of בן בוהיין to be such a minor problem and not as he explained by the אנשי יריחו that the problem is a more severe problem of eating tevel? It seems that Rashi understands that the case wasn't limited to turnip leaves where there was mistaken halachic justification, rather בן בוהיין knew that vegetables were exempt from Peiah, but was machmir on himself to make it hefer as if it were Peiach, as a chumra. His intent was to make it hefker so that it would truly be exempt from ma'aser, therefore the concern in the mishna of feeding tevel to the poor doesn't apply. Tosafos question also doesn't apply because the fact that it is effective in exempting from ma'aser by assuming a status of hefker is exactly the problem.

Pesachim 56a - Saying Baruch Sheim... Out Loud

The gemara says that we compromise in saying ברוך שם כבוד מלכותו between what Yaakov Avinu did of saying it loud and what Moshe Rabbeinu did (not saying it at all in the parsha of shema in parshas vaeschanan). Therefore, we say it, but we say it silently. Our custom on Yom Kippur is to say Baruch Sheim... out loud because of a special status we have. The Maharsha and Tzlach both point out that the issue with saying Baruch Sheim out loud is only a problem when being used as a break between the pasuk of Shema and V'Ahavta. Therefore, if one is not saying Shema, or is only saying the first pasuk of Shema Yisroel, they can say Baruch Sheim out loud.

This approach fits well with Rashi who explains that R. Meir in the Braisa considers כורכין את שמע to mean, without pausing between the pasuk of Shema and V'ahavta. Therefore, R. Yehuda argues and says that even if you are mafsik with a pause, it is not sufficient, because you need to be mafsik with the phrase of Baruch Sheim. Based on this approach, there is no question that the function of Baruch Sheim and the discussion of saying it loud or quietly is due to the hefsek between Shema and V'ahavta. However, Tosafos explains the problem with being כורכין את שמע and not being מפסיקין, doesn't refer to a hefsek between shema and v'ahavta, rather a hefsek between שמע ישראל and the word Hashem. According to this approach, there is no discussion at all regarding hefsek between שמע and ואהבת, therefore when R. Yehuda comes to argue on R. Meir and insists on the saying of ברוך שם כבוד מלכותו לעולם ועד, it would seem that after saying shema there is an inherent reason to say the pasuk of baruch sheim, not merely for the purpose of serving as a hefsek. Therefore, when the gemara concludes that we compromise to say it quietly, it may apply even in a situation where one is just saying the pasuk of shema and not the entire parsha, they should still say baruch sheim quietly and not out loud.

Pesachim 53b - Giving One's Life for Kiddush Hashem

The gemara cites a braisa in which Tudos darshens a kal v'chomer to explain why chananya misha'el v'azarya risked their lives by being throne into a fire, rather than bow to the idol of Nevuchadnetzar. They learned from the frogs of מכת צפרדע who jumped into the preheated ovens. Rashi explains that if not for the kal v'chomer the default should be וחי בהם ולא שימות בהם, therefore they had to learn from the frogs that they should forfeit their lives.

Tosafos asks that this was considered בפרהסיא, since it was a public spectacle. Therefore even if it weren't the more severe prohibition of avoda zarah, there is no concept of וחי בהם ולא שימות בהם, and the default is that you must give your life. Why was it necessary for them to derive this concept from the frogs since it is the halachic default? Tosafos answers that it wasn't a real Avoda Zara, rather it was an idol for the purpose of kavod, therefore it wasn't an actual aveira at all. Since technically they were not required to forfeit their lives, it was an extra level of Kiddush Hashem beyond what was required and therefore necessary to learn from the frogs. Tosafos would seem to be against the opinion of the Rambam (Yesodei HaTorah 5:4) who says that one is not allowed to be "machmir" on יהרג ואל יעבור, and is not allowed to give up their life unless the halacha demands it. However, the Kesef Mishna cites the Nimukei Yosef who says that an אדם חסיד who deems it necessary to be mechazeik an area of Torah that people are no adhering to, may make a decision to give up his life even in a time that is not necessary. This would justify the approach of חנניה מישאל ועזריה. The difficulty with this approach is that the gemara in Megillah 12a says that the Jews in the time of Achashveirosh were threatened because of the aveira they violated of bowing to "the idol". Rashi interprets that it refers to the idol of Nevuchadnetzar. According to Rabbeinu Tam who says that the tzelem of Nevuchadnetzer wasn't real Avoda Zara, it would be forbidden for the Jews to sacrifice their lives, so how could they be liable for not doing so? Perhaps Rabbeinu Tam would say that the tzelem being referred to is that of Haman (see Maharsha there) and holds like Rashi in the Megillah who says that the tzelem of Haman was actual Avoda Zara (against Tosafos in Shabbos and Sanhedrin in the sugya of worshiping out of ahava and yi'rah).

The Maharsha justifies Rashi's position by saying that even if it were bonified avoda zarah, it could be that Tudos held like the opinion in Sanhedrin 74a that even for Avoda Zara one does not need to sacrifice their life. Regarding the point of it being בפרהסיא, the Maharsha says that since it wasn't in the presence of 10 Jews, it doesn't qualify as פרהסיא even if it were in public (perhaps Tosafos assumed that since 10 Jews knew about it, it qualifies as פרהסיא even if it is not in their presence, as we find by Ester that the gemara Sanhedrin 74b considers פרהסיא since 10 Jews were aware that she was living with Achashveirosh - see Shach in Y.D.).

However, the Maharsha points out that due to the concept of וחי בהם - ולא שימות בהם, the entire kal vchomer learned from the frogs is ruined. How can they learn from the frogs who are not commanded in the mitzvah of וחי בהם, to themselves who are commanded in וחי בהם?

Both the Tzlach and the author of the Nesivos (R. Yaakov M'Lisa in sefer Emes L'yakov on parshas Va'eira) explain that when the gemara says מה ראו חנניה מישאל ועזריה שמסרו נפשן על קדושת השם, does NOT mean that they should have bowed down due to the mitzvah of וחי בהם. Rather, the question of the gemara is predicated on the fact that the kiddush hashem would only result if חנניה מישאל ועזריה would make it out alive, otherwise it would be a Chilul Hashem. The Emel L'yakov (here the he deviates from the approach of the tzlach) Kal V'chomer from the frogs was not whether they must or can allow themselves to be thrown into the fire, rather they learned from the frogs what would happen if they were to allow themselves to be thrown in. The kal v'chomer was that if the frogs who were not commanded on kiddush hashem, a miracle was performed so that they exited alive to enable a kiddush hashem, certainly for them who were commanded on kiddush hashem, Hashem would make a miracle to enable the kiddush hashem. Based on this approach, it wasn't an issue of sacrificing their lives because the kal v'chomer taught them that they would make it out alive.

Pesachim 50b - Lo Lishma

The gemara says that a person should always involve himself in Torah and Mitzvos even she'lo li'shma because it will lead to lishma. In my sefer, Nasiach B'chukecha (pg. 178) I cited the Dibros Moshe (Shabbos He'ara 92) who says that it would seem that something only qualifies she'lo lishma when it is being done for the purpose of a mitzvah, just that there is an ulterior motive it why it is being done. For example if one studies Torah for the purpose of receiving honor that it shelo lishma because their intent is to do the mitzvah of Torah study just that it is for a non-ideal objective. However, when one is so to speak mis'aseik in the doing of a mitzvah, and doesn't intend to even do the mitzvah, it should not even qualify as she'lo lishma and there should be no reward. However, Rav Moshe proves from this gemara of שפל ונשכר being as Tosafos describes a lazy person who abstains from doing work and happens to also not do work on erev shabbos, receives reward of shelo lishma. In this case his abstention from work is not for the intent of even doing a mitzvah, yet it still qualifies as shelo lishma for which he receives a reward.

There is an interesting question regarding שלא לשמה whether it has inherent value, or whether in and of itself is not significant but one receives reward since it will put them on the path of doing it lishma. We can derive from the gemara that even one who abstains from doing melacha out of laziness qualifies as shelo lishma, that the advantage of lo lishma is not inherent, rather just because the routine will eventually lead to lishma. ויש לדחות.

Pesachim 49a - Returning from a Mitzvah to destroy Chometz

The Mishna says that one who is on his way to shecht the korban pesach or do a bris milah and remembers having chometz at home, if there is time to return, destroy and still be able to do the mitzvah, that is what he should do. However, if there is a conflict so that by returning to destroy the chometz he will be unable to perform the mitzvah, he should just be mevatel the chometz and continue with doing the mitzvah. The rationale is as Rashi explains, since bitul is sufficient m'doraysa, chazal did not impose the requirement to destroy chometz if it will interfere with a mitzvah. The implication certainly is that in a situation where one cannot be mevatel their chometz because it is after the z'man issur, they will need to go back and destroy their chometz even at the expense of the mitzvah. Nonetheless, this point is a machlokes between the Magen Avrohom and Even Ha'Ozer. The Magen Avrohom says he would go back to destroy the chometz but the Even Ha'ozer says he would continue with the mitzvah and leave the chometz at home.

The Tzlach asks on the Even Ha'ozer, since the mitzvah we are speaking about is korban pesach, how can we allow him to shecht the korban pesach while he still has chometz since that will be a violation of a la'av of shechting the korban pesach while he has chometz? The Tzlach points out that in this situation it is not possible to suggest that the aseh of korban pesach would push off the lo ta'aseh of shechting the korban pesach while he has chometz because the concept of aseh docheh lo ta'aseh applies only when they happen to conflict, but a lo ta'aseh that specifically refers to the issur of having chometz in one's possesion while shechting the korban peach, cannot possibly be pushed off by the mitzvah of shechting the korban pesach.

Pesachim 36b -How D'rabonons impact D'oraysa

There are many areas of halacha where an issur drabonon can potentially impact a doraysa and the question is whether the Torah regards an issur drabonon to be permitted, or as an issur. For example the braisa says that just as one cannot be yotzei matzah with bikurim since it can't be eaten בכל מושבות, one should also not be yotzei with maaser sheini. Rashi explains that since maser sheini, once brought into yerushalayim can not be taken out to be redeemed, there is no heater to eat it בכל מושבותיכם therefore one should not be able to be yotzei their mitzvah of matzah. Rashi points out that the issur to take it back out and redeem it is only drabonon yet it would be a Torah recognized issur and prevent maser sheini from being regarded as something that can be eaten בכל מושבותיכם. Tosafos on 38a d.h. aval says this exact point in their second answer.

Similarly, when the gemara 35b says that one can't be yotzei matzah with tevel that is only tevel drabonon, rashi explains that the problem is מצוה הבאה בעבירה implying that even an issur drabonon will be regarded as an aveira and prevent the mitzvah doraysa from being fulfilled. However, the maharsha points out that an issur drabonon can qualify as an aveira for מצוה הבאה בעבירה but apparently not for the concept of מי שאיסורו משום בל תאכל חמץ לבדו that rashi quotes on the top of 35b from ravina on top of 36a.

A similar idea is found in Tosafos 29a d.h. ein, that an issur drabonon of not being able to redeem kodshim to feed to dogs can cause there not to be an issur doraysa of meila. Tosafos explains דכיון דאמרו רבנן אין פודין לא שויא מידי. However, Rashi 7a needs the concept of hefker beis din to explain why an issur hanaah drabonon would prevent kidushin doraysa. From the fact that rashi doesn't say simply that once the rabbonon don't permit benefit it is essentially worthless, implies that rashi holds an issur hanaah drabonon isn't considered worthless by the Torah.

Pesachim 27b - No Wood To Burn...

The gemara explains that the source for R. Yehuda that chometz must be burned rather than using other methods of destruction is a kal v'chomer from Nosar. The Rabbonon respond to R. Yehuda that if the source is going to be a kal v'chomer from no'sar (rather than a ma matzinu), chometz must be an absolute chumrah. However, here the chumra is a chumra that will lead to a kulah - לא מצא עצים לשרפו יהא יושב ובטל והתורה אמרה תשביתו שאור מבתיכם - If one doesn't have wood do burn chometz they will end up not burning it and be in violation of tashbisu.

Many Meforshim ask, that if one doesn't have wood to burn it they will be mevatel, thereby avoiding any problems. Why does the gemara assume that it will lead to a kulah since on a Torah level being mevatel the chometz is sufficient? Because of this question the kolbo (on of the rishonim) proves that chometz that one is aware of cannot be batul. Bitul is a special method that only works for chometz that one is unaware of. This approach can certainly not fit with Tosafos 21a (mentioned on this blog) who holds that for chometz that one is unaware of there is no violation of בל יראה ובל ימצא even without bitul. According to Tosafos biutl is only necessary for chometz that one is aware of, so it must be that bitul even works on chometz that one is aware of.

The Tzlach explains that according to Tosafos 12b who says that R. Yehuda demands burning only after the z'man issur, but prior to midday on erev pesach one can destroy chometz however they choose, there is no question. The Rabbonon are saying to R. Yehuda, after midday on erev pesach when one can no longer be mevatel (since it is already assur b'hana'ah) and you R. Yehuda insist on burning, it will lead to a leniency because one who doesn't have wood will not be able to fulfill tashbisu by destroying their chometz. 

Another approach is that according to Tosafos 4b that bitul is not learned from tashbisu, rather it is a method of hefker, the Rabbonon may be saying to R. Yehuda that if one would not have firewood they could not perform the mitzvas aseh of tashbisu. They can certainly rid themselves of chometz using bitul or other methods of destruction, but they would not fulfill the mitzvah of tashbisu. However, according to Rashi 4b who says that Tashbisu is the source of bitul, and Rashi on 12b who says that after the z'man issur one can use any method of destruction it would seem that bitul is a perfectly legitimate way to fulfill tashbisu prior to the z'man issur and other methods are fine after the z'man issur, so what is the Rabbonon's question on R. Yehuda?

The Tzlach explains that Rashi on 4b who says that bitul is learned from tashbisu goes according to the Rabbonon that chometz can be destroyed in any method one chooses, therefore bitul can also be a fulfillment of tashbius. But, according to R. Yehuda who insisits on burning, bitul is not a fulfillment of tashbisu.

Pesachim 25a - Refuah from Asheira Wood

The gemara says that in a situation of sakanas nefashos one is allowed to derive benefit from all items that are forbidden to benfit from i.e. orlah and kilei ha'kerem, but not from asheira wood. Although the gemara thinks originally that for pikuach nefesh one should be able to use asheira wood, the maskana rejects that. It seems that originally the gemara assumed that the issur to save one's life by doing avoda zara is only when they would be worshiping avoda zara, but here where they are merely benefiting from the avoda zara without worshiping it, the gemara thought that one would not have to give up their life to avoid that. The conclusion is that even to avoid benefiting from the asheira one would have to sacrifice their life.

The questions remains: Why? Why does one need to give up their life to avoid benefiting from avoda zara and not just for worshiping avoda zara?

Tosafos says that we are speaking about a case where the refuah element is not associated with the type of tree or anything physical, rather it comes from it being an avoda zarah tree. Since another tree of the same type that is not an avoda zara tree would not work, there is a concern that one will be drawn into the worship of avoda zarah since his life was saved using its powers. It would seem from Tosafos that this is a Rabbinic extension demanding יהרג ואל יעבור because using the avoda zara would inevitably lead to worshiping the avoda zarah. According to Tosafos, if one were using the physical components of the tree which just happens to be avoda zara, there is no concern.

The Ran has a different approach. He understands that included in the issur of avoda zara is the worshiping of avoda zara וכל אביזרייהו. Just as by גילוי עריות one must give up their life to avoid even the אביזרייהו of giluy arayos, avoda zara would be the same. By using avoda zara for refuah, one would be in violation of לא ידבק בידך מאומה which would be an איזרייהו דעבודה זרה, therefore one must give up their life to avoid it. The Ran holds that any la'av that is specific to avoda zara (or one of the big 3 aveiros), even one that you aren't חייב מיתה for it, you must give up your life.

Rashi seems to have a third approach. Rashi writes that using avoda zara to heal oneself is נראה כמודה בה, looks like you are agreeing and recognizing it, therefore one must avoid that even at the expense of their life. Rashi is difficult to understand. Is this concept of נראה כמודה בה an actual issur of avoda zarah? It sounds like some form of מראית עין where people will think that you are are recognizing the avoda zara even though you aren't. Why would one have to give up their life for that? 

It seems to me that this can be explained based on the sugya in Sanhedrin 61b where Abaye and Rava argue whether avoda zara מאהבה ויראה qualifies as avoda zara. Abaye focuses on the persons actions and therefore holds that you are chayev, whereas Rava focuses on the mindset and says that since you don't accept it as a GOD and are only doing it out of fear or intimidation, you are patur. Even Abaye admits that in a situation where one is not at all accepting the avoda zara as a G-d such as standing in a church bowing down to an idle but thinking he's in a shul bowing to Hashem, it doesn't even qualify as a shogeg of avoda zara - אי קסבר בית הכנסת הוא והשתחוה לו, הרי לבו לשמים. Rashi points out that even if one were standing in a beis avoda zara, well aware of where he is and bows down with intent to Hashem, there is no punishment for worshiping avoda zara. Clearly we see that avoda zara is not violated by action alone. It is only violated when one intends to accept it as a god.

Being that avoda zara is only violated when one intends to worship, why do we ever require יהרג ואל יעבור by avoda zara? Why don't we just tell the person to have in mind to serve Hashem? Clearly, the obligation to sacrifice one's life is not just to avoid the technical violation of avoda zara. Doing an action that seems like avoda zara, even בצנעה with no one watching  is a violation of ואהבת את ה' אלקיך for which one needs to sacrifice their life as we learn from בכל נפשך. Here too, Rashi is saying that since using asheira gives the impression of being מודה בה, even if no one is watching, one must give up their life. The din of יהרג ואל יעבור for avoda zara is not to avoid an issur avoda zarah, it is to avoid a violation of ואהבת את ה' אלקיך. Any connection to avoda zara that chazal deem a violation of אהבת השם one must give their life to avoid.

Pesachim 24b - Ta'am Ki'ikar

At first the gemara thinks that consuming the juice of fruits of orla is not a normal way to eat the fruit and therefore qualifies as שלא כדרך הנאתו. The gemara concludes that the rationale to permit fruit juice of orla is permitted because we regard the juice as being זיעה בעלמא - sweat of the fruit without the real taste and therefore isn't considered to be eating the fruit of orla.

Tosafos asks a fundamental question. We pasken that טעם כעיקר is d'oraysa (unlike Rashi in chulin). How could the fruit juice be any less significant than ta'am ki'ikar? Tosafos leaves the question unanswered.

The gemara says in Brachos that one makes a shehakol on fruit juice because it isn't considered the fruit, rather just זיעה בעלמא just as the gemara says in the context of orlah. However, in Brachos 39a the gemara says that on vegetable soup (beat soup) one would make a בורא פרי האדמה. Tosafos writes that there is a difference without articulating the difference. The Rosh (18) explains that the vegetable soup has the taste of the vegetable and therefore deserves the same bracha as the vegetable. But the juice of a fruit doesn't have the taste of the fruit. The Rosh then adds - ואפשר שאם בישל הפרי ונכנס טעם הפירות במים מברך עליהן בורא פרי העץ. The Rosh seems to understand that the cooked juice of the fruit contains the full flavor of the fruit, whereas squeezing out the cold juice doesn't capture the full flavor.

The Rashash indicates that this is also the rationale for why we don't forbid the juice of orlah fruits based on ta'am k'ikar. Although if one would cook the fruit, the full taste of the fruit would come into the water therefore it would be included in the issur orlah, but without cooking the fruit we would not give the juice a status of the fruit based on ta'am k'ikar.

It seems that the ואפשר of the Rosh, implying that he isn't entirely convinced, is entertaining the possibility of the distinction between fruits and vegetables. Perhaps only by vegetable soup would we say that one makes a borei pri ha'adama, but a fruit soup would be she'hako, not ha'eitz. However, the Rosh leans toward the approach of not distinguishing between fruits and vegetables. Therefore, any water in which the fruit or vegetable was cooked in would obtain the bracha status of the fruit or vegetable.

The Rashba (cited in divrei chamudos) considers the distinction to be whatever is normal and regular to be eaten that way. Fruits are eaten by eating the fruit, not squeezing the juice and not making a soup, therefore if one would either squeeze out the juice or cook a soup with it, the bracha would be she'hakol. But, vegetables which are routinely cooked and turned into a soup, the bracha would be ha'adama. Based on this approach, there is no difference between cooked soup and squeezing a fruit, either way the taste may be significant, but since its not a normal way to eat the fruit the bracha would be she'hakol. According to this approach, it remains difficult to understand why fruit juice of orlah would not be אסור מדאורייתא based on the concept of טעם כעיקר.

Pesachim 23a - Doing Business with Prohibited Foods

In the discussion trying to prove whether the language of "don't eat" in the torah, automatically includes the prohibition to benefit, the gemara tries to prove the point from sheratzim which are permitted to receive benefit from even though it says לא יאכל (yei'achel) which is a question even on Chizkiya. The gemara answers that although the language of "yei'achel" implies an issur hana'ah, the Torah writes לכם to imply that שלכם יהא, and permit benefiting from it. To which the gemara asks, if so it should permitted to benefit from it even lichatchila, why does the braisa say that one cannot be in the business of buying and selling non-kosher animals. The gemara responds that the pasuk also says יהיו - בהוייתן יהא. The Taz in Y.D. 117:16 points out that the contradiction in the pesukim that forbids selling lichatchila, but if it comes your way you can sell it and receive benefit, is the source that one is not allowed to buy and sell prohibited foods. The gemara implies that the prohibition to do business with forbidden foods is d'oraysa, because it is derived from the contradiction in the pesukim שלכם implying its permitted and יהיו implying that its forbidden. The compromise is that it is not an issur hana'ah but an issur to do business with forbidden foods (unless one just happens to end up with it).

Tosafos d.h. amar, says explicitly that it is an issur d'oraysa. However, Tosafos limits the issur d'oraysa to include only selling items that are eatable. One can process soaps and lotions from non-kosher animals.

The Rashba (cited in Taz) disagrees and holds that the nature of this issur is only d'rabonon due to a concern that one may come to eat from it. The gemara strongly supports Tosafos against the Rashba.

Pesachim 21a - Is one in violation of owning chometz that they don't know exists?

Generally speaking we assume that בל יראה ובל ימצא have nothing to do with actually seeing or finding chometz. The braisa on 5b makes it clear that hiding chometz so that one doesn't see it, accomplishes nothing to avoid the issurim. However, in that context we only include in the issurim chometz that one is fully aware of. There is a big machlokes Rishonim (Tosafos 21a and Rosh 6b) whether one is in violation of בל יראה ובל ימצא on chometz that they are completely unaware of, even without being mevatel it.

The gemara on 21a says that if we were only told that one can leave chometz in a place where there is a חיה, that is because a wild animal has a tendency to hide the chometz, but a more domesticated animal that will not hide the chometz, rather leave it out in the open causing the violation of בל יראה ובל ימצא, we would think that it is forbidden to feed them prior to pesach. The gemara seems strange. How does the wild animal hiding the chometz help the owner avoid בל יראה ובל ימצא? Tosafos derives from here that any chometz which exists in a hidden place that the owner is unaware of is not subject to the issur of בל יראה ובל ימצא. Unlike בל יטמין which is assur because the owner knows where it is, here the owner doesn't know where it is. Based on this, Tosafos explains the question of the gemara 6b, why must one be mevatel on the night before erev pesach, just be mevatel when you find it? The gemara answers you may find it after it already became issur when it is already too late to be mevatel. Tosafos understands that the gemara knew all along that we were speaking about finding it once it has already become assur, yet being mevatel at the point when you find it would be sufficient because until you find it there is no violation and when you find it you will immediately be mevatel. To which the gemara answers that after the chometz becomes assur bitul is not longer a possibility.

However, the Rosh 6b explains that by the Torah writing לא יראה rather than  לא תראה it implies that one cannot have chometz in any area that it is fit to be seen, even if now it is not known about and not seen. Therefore, if a person was lax on bedikas chometz and found chometz on Pesach that they were not mevatel, according to the Rosh they were in violation of בל יראה ובל ימצא the entire time. Whereas Tosafos will hold that they were not in violation until they find it since they didn't know about it, and even when they find it they are not in violation so long as they are busy trying to destroy it (as tosafos writes 29b d.h. rav ashi).

According to the Rosh, the gemara 6b which suggests to be mevatel when you find it was assuming that one would find it prior to the z'man issur when bitul was still possible, to which the gemara is mechadesh that we are concerned that he will find it after the z'man issur. Therefore, without being mevatel in advance he will be in violation from the moment of the z'man issur even though he has not idea that it even exists.

Pesachim 7a - Bracha of L'hachniso

The gemara says that the "lamed" implies that one is making a bracha on a mitzva that they are about to do, however, the language of "al" is a machlokes whether it has an implication of a mitzvah that one is about to do, or whether it is more applicable to a mitzvah that has already been done. Another implication that the gemara assumes is that if made with a "lamed" the implication is that the obligation is specifically on the person making the bracha more than anyone else, whereas the language of "al" is more appropriate when the person doing the mitzvah is not the person on who the primary obligation falls. When the gemara concludes that on biur chametz we make "al", the gemara is paskening like the opinion who says that "al" also implies a mitzvah that you are about to do. Rashi understands that the gemara also retracts from the second assumption and holds that even if the one making the bracha is the one who is has the primary obligation, he still makes "al". Rambam disagrees and maintains that when the father does the milah or someone shechts his own korban pesach, he makes la'mul and lishchot, not "al hamilah" and "al ha'shechita".

Based on these rules that a bracha made with a lamed is always done before the act, Tosafos cites the Rashba who says that the father of a child getting a bris should make the bracha of li'hachniso prior to the milah. Since li'hachniso is made with a lamed, it must be made before the bris. Furthermore, the gemara 7b says that all brachos should be made prior to doing the mitzvah. Rabbeinu Tam disagrees because the gemara in Shabbos implies that li'hachniso is made after the milah. Rabbeinu Tam explains that the nature of the bracha of l'hachniso is not a birchas hamtizvah on the mitzvah that is presently being done, rather it is a birchas ha'shvach to praise and thank Hashem, and its function is to show that the bris is being done li'shma, not for medical purposes or chas v'shalom avoda zara purposes.

Presumably, Rabbeinu Tam's approach explains why the bracha doesn't need to be made prior to the mitzvah both from the perspective of the language "li'hachniso" and from the perspective of all brachos need to be made prior to the mitzvah (כל הברכות מברך עליהן עובר לעשייתן). However, Tosafos adds that the reason it doesn't need to be made prior to the mitzvah is that the bracha is only made before when the one doing the mitzvah makes the bracha, but here since the father is not actually doing the bris, there is no halacha of כל הברכות מברך עובר לעשייתן.

The question is why Tosafos needs that addition. Once Tosafos establishes that this is not a birchas hamitzvah, it should follow that it doesn't need to be made prior to the mitzvah even if the one doing the mitzvah makes the bracha. Clearly, Tosafos holds that being a birchas ha'shevach and not a birchas hamitzvah only solves the language issue of using a lamed "li'hachniso", but doesn't address the issue of making brachos prior to the mitzvah because even birchas hashvach should be made prior to the mitzvah. However, the Maharsha points out that the Rosh uses the sevara of being a birchas hashevach to solve the problem of עובר לעשייתן also. Therefore, there is a machlokes Tosafos and Rosh whether birchas ha'shevach need to be prior to the mitzvah.

Tosafos proves that the bracha of li'hachniso can be made after since it is made by someone else from birchas eirusin that we make after since it is made by someone else. The Rambam (Ishus 3:23) holds that birchas eirusin is a standard birchas hamitzvah and is therefore made before the mitzvah is done. The Rambam writes that making the bracha after the kiddushin is a bracha l'vatala. The Ra'avad seems to agree that it is a birchas hamitzvah but says that it should be made afterward since there is a concern that they will not go through with it. Similarly, li'hachniso is made afterward since there is a concern that the mohel won't do the bris. The Ra'avad essentially says that same as Tosafos that when someone else is doing it you don't need to make the bracha before, except that the Ra'avad gives a practical reason for this that we are concerned that they will not go through with it.