Baba Metzia 37a - Yotzei Yidei Shamayim

The gemara concludes that the entire mishna is discussing being yotzei yidei shamayim when the nifkad is claiming to have money of others but they are not making definitive claims against him (only ta'anas she'ma). Therefore, when one steals or receives a pikadon and should know how much he owes to each, when he doesn't know it is recommended that he fulfill his obligation to be yotzei yidei shamayim and repay each of them. But, when two people together handed him packages in a way where he is not expected to remember who gave what, when he can't recall who gave what, there isn't even a yotzei yidei shamayim requirement on him to pay back both. The Shulchan Aruch (c.m. 300:1) writes that when 2 people give a pikadon to a third, each giving different amounts, if each claims that he gave the higher amount he is actually obligated to fully repay each of them since he should have written their names on the packages. But if they are not making claims against him, rather he is approaching them and claiming that he has their money but not sure to whom he owes the higher amount (ta'anas she'ma), he is not obligated to pay them both the higher amount but should do so to be yotzei yidei shamayim. This is all assuming that they gave it to him separately, but if they handed it to him together in one bundle (or according to rashi at the same time is tantamount to one bundle) - in way where he isn't obligated to recall who gave what, even if each one claims the higher amount, he is not obligated to pay the higher amount to both. The rationale is that he can claim that when they originally gave it to him together, they indicated that they were not makpid on each other. Even to be yotzei yidei shamayim he is not required to pay both.

The ketzos raises a question from the Shulchan Aruch (222:2) who rules that if one purchases an item from a store and can't recall which store he purchased it from, he would be obligated to be yotzei yidei shamayim by paying each one of the 5 stores that he may have purchased from. Why is there a greater chiyuv to be yotzei yidei shamayim in that case? (The assumption is based on tosafos that in the case of the sale he is also not required to recall which of the stores he purchased the item from). 

The ketzos (siman 300) explains that there is less of a responsibility by pikadon because wherever it is, it is considered to be in the reshus of the owner. The nifkad isn't responsible in a chiyuv "hashava", he is just responsible for any negligence on his part. Therefore, when they gave it to him in a way that he wasn't negligent, he is not required to return it. But, one who owes money for a purchase on the other hand, it is like a debt that he owes, and therefore it is his responsibility to make sure that he fulfills his mitzvah of "hashava" even if he wasn't at all negligent.

The Ketzos (222) makes a different distinction based on the language of the Shulchan Aruch/Rambam - ואם הוא חסיד נותן דמים לכל אחד ואחד כדי לצאת ידי שמים

The type of yotzei yidei shamayim being spoken about by the case of the sale is not for everyone, it is only for one who considers himself a chassid. However, normal people wouldn't be obligated even to be yotzei yidei shamayim. Therefore, in siman 300 where we are speaking about the obligation of regular people, the shulchan aruch writes that one isn't required even to be yotzei yidei shamayim.

Baba Metzia 33a - My Aveida Comes First

The gemara says that one's own aveida comes before an aveida of someone else. This is learned from a pasuk of אפס כי לא יהיה בך אביו - שלך קודם לשל כל אדם. This drasha would make sense in a situation where it is a very valuable item and the loss would lead to poverty, but how does this explain why one has the right to retrieve his own coat before that of someone else - that won't lead to poverty? I found the answer in the pirush hamishna of the Rambam:

והרמז מן התורה שיש לאדם להקדים עצמו על זולתו, הוא דאמר רחמנא וכו' כאילו אמר אין אתה חייב להסיר רעה מאחר אלא כשלא יבא לך כעין אותה רעה, שהסירות ממנו כי אם תהיה בענין שאם תתן לאביון די מחזורו תשוב אתה עני כמוהו אינך חייב לתת לו

The rambam interprets this as a mashal. Just as when protecting oneself from poverty he has the right to prioritize himself over others, so too when it comes to protecting his property on a smaller scale he has the right to prioritize himself over others.

But the gemara warns - כל המקיים בעצמו כך סוף בא לידי כך. Rashi explains that this is a warning that in general a person should go lifnim mishuras hadin and prioritize his friends aveida, unless it is a "hefsed mochi'ach" - meaning that his loss is definite and not just a possibility. Rashi seems to hold that me'ikar hadin one has the right to prioritize a safeik loss to himself over a definite loss to someone else, but recommends that one go lifnim mishuras hadin and forfeit any safeik loss to himself when there is a definite loss to someone else. But, a definite loss to himself he is not obligated to forfeit even lifnim mishuras hadin.

Baba Metzia 32 - Charging for Mitzvos

There is a well known rule that the gemara establishes in Nedarim 37a that one is not allowed to charge for the performance of a mitzvah such as teaching torah. This seems to create a difficulty in our gemara where the chachamim hold that one can charge for loading but not for unloading. How can one charge for loading, it is a d'oraysa mitzvah? Simply, this can be answered by saying that the default position is that one cannot charge for a mitzvah, but being that we have an extra pasuk (since we could learn out both loading and unloading from the pasuk of te'ina as the gemara explains), the extra pasuk is indicating that this breaks the regular rules and one can indeed charge for loading. However, Rashi complicates matters further because rashi (d.h. lomar licha) says that if the torah would not have written the mitzvah to unload, and we would have learned it from the mitzvah to load, we would have said that one MAY CHARGE for both loading and unloading. The maharsha points out that Rashi holds that the default without any extra pasuk is that one can charge for both prika and te'ina - the extra pasuk requires that one to prika free of charge. Therefore, the question would return, how can the default be that one can charge for a mitzvah, since in general one is not allowed to charge for a mitzvah? It can't be that the charge is only compensation for loss as we find by aveida, because then the gemara should have been clear about that.

A similar question can be asked when the gemara 32b suggests that one would be obligated to help unload an animal even when techincally the mitzvah of prika wouldn't apply i.e. the animal is overloaded or the owner isn't willing to help. The gemara explains that the requirement to help unload even without the specific mitzvah of prika would indicate that tza'ar ba'alei chaim is d'oraysa. Yet, the gemara says clearly that one would be allowed to charge for their assistance in unloading since they are not compelled by the mitzvah of prika, rather by the mitzvah of tza'ar ba'alei chaim. The question is, what is the difference whether the torah requires him to unload based on prika or based on tza'ar ba'alei chaim, it is a mitzvah of the torah that one cannot charge for? Perhaps the gemara understands that tza'ar ba'alei chaim doesn't place any specific demands on the individual. Rather, it is a torah recognized concept that would obligate one who witnesses a suffering animal to help alleviate the pain. It is only when the torah recognizes a specific action such as teaching torah, or healing the sick, do we say that one may not charge - מה אני בחנם אף אתם בחנם. But when one is compelled by a torah recognized concept, not by a specific mitzvah in the torah they have a right to charge.

Baba Metzia 32a - Kibud Av vs. Mitzvah

Today my father has the 50th yahrtzeit for his father 

לעילוי נשמת אברהם בן חיים יצחק ע"ה

The gemara says that since kibud av is such a great mitzvah, one would have thought that if a father told a son to violate an aveira such as entering a cemetery (for a kohen), or not to return a lost object that the son should obey the command of the father. The gemara requires a special pasuk of "ani hashem" to teach that the son shouldn't listen to his father to do an aveira. Tosafos writes in Kiddushin 32a that the case where the father tells the son not to return the aveida cannot refer to a case where the father says "don't return that aveida" because then it is obvious that the son should not listen and we wouldn't need a pasuk to teach that. Rather the case that the pasuk comes for is when the father says to the son "get me a glass of water" and the son is faced with the conflict of kibud av or hashavas aveida.

Why is it so obvious that if a father would tell a son not to return an aveida, that the son should not listen? Why is a pasuk not necessary to exempt the son from listening to his father in that case? 

The ya'avetz in kiddushin says that by the father telling the son not to do the mitzvah of hashavas aveida for no rhyme or reason, the father is a rasha, so the son shouldn't listen. In truth though, whether or not there is a mitzvah of kibud av for a father who is a rasha is a machlokes shulchan aruch and rama (240:18). According to the ya'avetz the tosafos would conform with the opinion of the rama.

However, the ritva in baba metzia says that since this type of command does not provide any benefit to the father, this type of command is not included in the mitzvah of kibud av. The Gr"a at the end of hilchos kibud av (240:36) quotes this opinion in the name of the Ramban and Rashba:

לפי שאין עיקר כיבוד אלא במה שיש לו הנאה כמש"כ בקדושין לא ע"ב איזהו כיבוד וכו' אבל אמר לו לעשות דבר שאין לו בה הנאה וכו'ומה שכתב "יכול א"ל אביו היטמא" לא לחנם אלא להביא פירות מבית הקברות וכיוצא וכן אל תחזיר כדי שלא יבטל מלהאכילו

The difference between the approach of the ritva and the ya'avetz is if the father would tell the son "don't return the aveida, rather get me a glass of water" - based on the ya'avetz one can argue that this would also render the father a rasha so we wouldn't need a pasuk to exempt the son. But according to the ritvah this would be a case where there is a mitzvah of kibud av so we would need a pasuk to exempt the son.

In short, the gemara according to tosafos compels one of the two halachos - either there is no mitzvah to listen when the father receives no benefit, OR there is no mitzvah to listen when the father says to do an issur since by the command he renders himself a rasha.

The Pischei Teshuva (14) has a discussion about a father who tells his son not to say kaddish for the mother - should the son listen? The maharshal says that the son shouldn't listen since it would be like a violation of an issur d'rabonon. But the birkei yosef challenges this notion whether saying kaddish is actually considered an issur d'rabonon since in truth it is no more than a custom. However, the pischei teshuva writes that the son shouldn't listen because even if kaddish is not a real mitzvah, the father by giving a command not to say kaddish for the mother would be in violation of ואהבת לרעך כמוך. This implies that although it is not an issur from the perspective of the son, since the father renders himself a rasha through his command, the son shouldn't listen. Being that we follow the rama and hold that there is a mitzvah to listen even if the father is a rasha, perhaps the son should listen. 

Nonetheless, based on what we said above, Tosafos compels that either there is no mitzvah of kibud av on something that he receives no benefit from, or that there is no mitzvah to listen to a father who is a rasha. Therefore, in the case where the father would render himself a rasha through his command AND he is giving a command that he receives no benefit from, we are compelled according to both explanations of tosafos to say that the son shouldn't listen to the father.

Baba Metzia 30b - Zaken V'eino l'fi k'vodo - Hitting with a stick

מלשון הגמ' דכל המתחיל במצוה אומרים לו גמור משמע שהוא רק חומרא בעלמא, אבל יש להביא ראיה מסוגיא דידן דהוא חיובא מעיקר הדין

בגמ' בב"מ ל ע"ב מבואר דזקן ואינו לפי כבודו פטור ממצות השבת אבדה דילפינן מקרא ד"והתעלמת מהם" דפעמים שאתה מתעלם. אכן, קאמר רבה הכישה חייב בה. ונחלקו הראשונים בפירוש דבר זה, רש"י מפרש וז"ל הכישה הכאה אחת להשיבה נתחייב בה לאהדורה הואיל והתחיל עכ"ל. אבל בתוס' כה ע"ב בד"ה ואם, מפרשים על פי הסוגיא דבב"ב פח ע"א דדוקא בבעלי חיים דאנקטינהו נגרי ברייתא, ולא בשאר דברים. הרי דעת התוס' דטעמא דהכישה לאו משום שהתחיל במצוה אלא משום שגרם גריעותא בשמירתה וממילא חייב לתקן מה שעוות ולאהדורה לבעלים, וזה שייך רק בבע"ח ולא בשאר דברים. אבל רש"י מפרש דקמיירי רק כשהכישה על דעת להשיבה, דנהי דפטרינן זקן ואינו לפי כבודו היינו רק כשלא הגביה החפץ ולא התחיל במצותה אבל כשהתחיל המצוה חייב לגמרה. וכעין סברא זו מצינו בגמ' כז ע"א בהא דרבנאי דיליף מקרא ד"ומצאת" דפטור מלהשיב אבידת נכרי אע"ג דאתא לידיה, דאילולי קרא הוי פטרינן ליה רק מלטרוח אחריה אבל אי נקטה חייב לאהדורה כדפרש"י שם. אלמא שיש סברא לפטור רק קודם שנטלה אבל כשכבר נטלה והתחיל במצות השבה מחוייב לטרוח ולהתעסק בה עד שמגיע ליד הבעלים. נמצינו למדים מפרש"י שיש חיוב גדול לגמור המצוה שהתחיל בה, וק"ו הוא, מה זקן ואינו לפי כבודו שפטור ממצות השבה כיון שהתחיל בה חייב להשיבה כ"ש אחרים שהתחילו במצוה שהם מחוייבים בה שחובה מוטלת עליהם לגמרה. 

אמנם לפי האמת נראה, שאין זה מקושר להא דמתחיל במצוה אומרים לו גמור. אלא רש"י לשיטתו אזיל בדף כו ע"ב דמצות השב תשיבם אינו מתחיל בשעת הראיה רק בשעה שנטל החפץ, לפיכך סובר רש"י דהא דפטרינן זקן ואינו לפי כבודו מ"והתעלמת מהם" היינו לפטרו מלעבור על לאו דלא תוכל להתעלם, ולא לפטרו ממצות עשה דהשב תשיבם. וכן נראה לפרש בכוונת רש"י כו ע"א בהא דרבנאי דבעי קרא יתירא ד"ומצאת" לפטור מלהשיב אבידת נכרי אף אחר שבאה לידו, דלולי קרא הוי פטרינן ליה רק מלאו דלא תוכל להתעלם ולא מעשה דהשב תשיבם. היוצא מדברינו דהא דפרש"י שהכישה והתחיל במצוה שחייב לגמרה, אין הטעם משום שהמתחיל אומרים לו גמור, אלא שלא פטרינן ליה רק מהלאו ולא מהעשה, וכיון שהעשה מתחיל בשעה שנטלה כשנטלה מחוייב להשיבה

Baba Metzia 30a - Your Need vs. Aveida Need

The gemara seems to understand that one can spread out an aveida for it's need but not for personal needs. But, the gemara questions whether one can spread out an aveida when it is לצרכו ולצורכה, both for the aveida need and for his personal need. The gemara tries to prove that it is permitted, but is unsuccessful in being able to prove it.

The Mishna seems to weigh in on this issue and clearly holds that לצורכו ולצורכה is permitted, because the mishna allows one not only to air out a sefer but even to read from it. Clearly, the mishna is permitting even personal use, so long as it has to be done for the purpose of the lost object. Tosafos explains that the gemara is reluctant to permit לצורכו ולצורכה because one is likely to do it for ONLY personal needs which would surely be assur. The prohibition of לצורכו ולצורכה is not me'ikar hadin, rather it is a d'rabonon gezeira that one shouldn't use it לצורכו ולצורכה because it may lead to using it for personal use. Therefore, by a sefer where the mishna gives specific instructions how and when to use it, there is no concern that he will take advantage so the rabbonon never imposed an issur. Based on this approach, the gemara that tries to prove that it is assur from the case of Eglah Arufa is difficult to understand. How does the fact that egla arufa becomes passul m'doraysa לצורכו ולצורכה, prove that the rabbonon are concerned that if one uses an aveida לצורכו ולצורכה it will lead to using it for only personal use? Tosafos will be forced to learn the question that the prohibition of לצורכו ולצורכה is that the rabbonon were afraid that you may come to use it only for personal use and therefore imposed a p'sul even when it is done לצורכו ולצורכה as if it is entirely being used for personal use. Here too, we should make a gezeria that even לצורכו ולצורכה is considered as if it were only used for personal use and pasul. The gemara answers that the p'sul is d'oraysa and therefore has no connection to our question.

The chofetz chaim (ahavas chessed 7 - footnote 2) understands that the Mordechai and rashi in pesachim disagree with Tosafos and hold that לצורכו ולצורכה is assur m'ikar ha'din, not just a gezeira that it will lead to personal use. Meaning, we view לצורכו ולצורכה on a d'oraysa level as if it were being used only for personal use and therefore assur. This is a tremendous chiddush because the action that is being done is entirely permitted, just that the intention is assur and would render the entire action an issur. But, based on this approach the proof from egla arufa works out better.

Baba Metzia 28a - Is a Siman Muvhak better than a Siman?

Rava says that even if siman is d'oraysa, it would still not measure up to eidim, therefore we would return the object to the one who provides the eidim (rashi). The Maharshal points out that the gemara is only able to tell us that eidim trump siman after it established that siman is d'oraysa, which implies that this would not have been the halacha in a case of siman muvhak against eidim. Rather, we would leave it until Eliyahu comes, because siman muvhak is just as good as eidim. The Shach (267:7) disagrees and holds that eidim is better than a siman muvhak. The shach understands that there is no more of a chiddush in saying that eidim is better than siman muvhak than saying that eidim is better that a standard siman which is d'oraysa. This would imply that if siman is d'oraysa and we have siman against siman muvhak, we would not return it to the siman muvhak, rather we would leave it. Pischei Teshuva quotes R' akiva eiger who is not sure about what to do when siman is up against siman muvhak. The question is that the gemara makes it clear that we always follow the better siman. If one gives the dimensions of length and width and the other only knows the total, we return it to the first. Based on this it should seem obvious that we return it to the one with the siman muvhak, because even if both are d'oraysa that is certainly the better of the two simanim?

To answer for the Shach and r' akiva eiger (who at least considers this an uncertainty), it seems that really we don't follow the better siman. Meaning, if siman is d'oraysa and both provide a siman it doesn't matter that one is slightly more specific than the other, and therefore we are required to hold the object until Eliyahu comes. Therefore in the case of siman muvhak against a standard siman which is d'oraysa we also don't return it to either one. However, the case where one gives the specific dimensions of length and width and the other gives the total, since the siman of the first completely includes the second and adds to it something more specific, it is as if the second has no siman at all and we return it to the first. But if both simanim are completely different even if the second is better we don't return it.

Baba Metzia 26b - Hashavas Aveida

Rava says that if one takes an aveida prior to yi'ush with the intent of returning it, and then decides after yi'ush to keep if for himself, he is in violation of "השב תשיבם". Rashi understands that he is only in violation of השב תשיבם, because the issur of gezeila only applies at the time that one grabs it (as rashi writes in many places), and the issur of לא תוכל להתעלם applies only at the time that one ignores the object by not picking it up. Rashi understands that the issur of לא תוכל להתעלם only applies until the object is picked up, but once the object is picked up for the purpose of returning it, the only prohibition left to be in violation of is hasheiv tishiveim. The Ba'al Hameor disagrees and holds that just as Hasheiv Tishiveim applies until the object is returned to the owner, so too לא תוכל להתעלם applies until the object is returned. Tosafos cites a braisa in kiddushin 34a that supports Rashi, which compels Tosafos to be go'reis in the gemara clearly like rashi - אינו עובר אלא משום השב תשיבם. The braisa in kiddushin lists the aseh of "השב תשיבם" as a mitzvah that is not time bound, thereby obligating women. The question is that would would anyway be obligated due to the negative prohibition of לא תוכל להתעלם? Tosafos therefore holds that there must be a case where the mitzvah of "hasheiv tishiveim" applies and the issur of לא תוכל להתעלם  doesn't apply, such as our case where the object is taken for the purpose of returning and then the finder fails to return it.

Baba Metzia 26a - Kinyan Chatzer

The gemara says that if one finds an old rusty object in a wall, he can assume it was there prior to the jews conquering eretz yisroel and therefore the finder can keep it. Tosafos asks, why doesn't the wall work as a chatzer for the owner to acquire the object that was in it, since a kinyan chatzeir doesn't need awareness of the owner to be ko'neh (it works as a shli'ach to acquire a zechus even without the owner knowing)? Tosafos answers that a chatzer can only acquire something that would definitely have been found by the owner, but doesn't have the ability to acquire something which may have never been found.

The Shita mikubetzes answers Tosafos question that a chatzer can only acquire without the owners knowledge when the owner owned it prior to the object coming into it, but in this case where the object was already in the chatzer at the time it was acquired, there isn't any kinyan chatzer. The Ketzos HaChoshen (198:2) uses this to explain the Shach who says that chatzer can only work when it is owned or rented prior to the object entering, but if the object was already in the chatzer, one cannot acquire the object simultaneously with acquiring the chatzer. However, it seems that the Shach goes beyond the chiddush of the Shita mikubetzes. The shach is speaking in a case where the owner of the chatzer is well aware of the object and interested in acquiring it through his chatzer, yet he insists that the chatzer cannot function to acquire an object that was already there when he acquired it. But in our case the owner is not aware of the object. Had the owner been aware of the object it is very possible that the shita mikubetzes would agree that he can acquire the object that was already in the chatzer when he purchases it. The reason that the shita would make a distinction whether or not the owner is aware of the object is that his sevara for not allowing kinyan chatzer to work on an object already in the chatzer is an issue with da'as. Meaning, whatever a person does not have da'as on at the time he acquires it, he isn't ko'neh - just that normally a person who owns a chatzer has stam da'as to acquire an object that would come into the chatzer afterward, but his da'as is not on objects that are already in the chatzer that he is unaware of. Therefore, if he is aware of the object, the kinyan chatzer has the ability to enable him to acquire even objects that were there prior to acquiring the chatzer.

Baba Metzia 25b - When to leave an aveida where it is

Tosafos explains that there are 3 types of places. 1. If an object is found in a place where it isn't at all protected it has regular rules of an aveida - with a siman it must be returned, without a siman we assume the owner was miya'esh so the finder can keep it. 2. If an object was found in a place where it is well protected then it should not be touched, and even if the finder accidentally takes it he can return it to the place that he found it (unless there is a chance that the owner came back and didn't find it there, in which case he must track down the owner and return it). Regardless of whether it has a siman or not, it shouldn't be touched. 3. If an object was found in a place where it is partially protected, but there is a possibility that it will be damaged - with a siman it should be returned, but without a siman he should leave it there.

In the third category where the place is semi-protected and the object doesn't have a siman, so that it should have been left there and not touched, if the finder accidentally picked it up he must hold on to it and not return it to it's original location. This is the concept of ספק הניח לא יחזיר, meaning that if you aren't sure if it was intentionally placed there or lost, you shouldn't touch it, but if you took it you can't "return it to it's original place". Why? Because you become a watchman over it, which makes you responsible to return it to the rightful owner.

Why in the case where the area was only semi-protected does the finder who picked it up assume status of a shomer that prevents him from placing it back down, but when the area is fully protected he doesn't become a shomer and can put it back down? Tosafos holds that the finder becomes a shomer who is responsible to do whatever would be in the best interest of the owner in both situations. If the area is well protected it is in the best interest of the owner to have it placed back down, but if the area is not well protected then it is in the best interest of the owner that he hold on to it.

Rashi here and later on daf 37b understands the words ספק הינוח לא יחזיר to mean that the finder cannot return it to the person who claims to be an owner and fails to provide a proper siman. The reason is the same - since he is a shomer on the item he has a responsibility to hold on to it until he finds the person who can prove himself to be the owner, and not return it to the wrong person. Tosafos asks on rashi that it is pashut that it shouldn't be returned to the person who claims to own it without a siman, just as with any aveida - why does it have to say it? Perhaps rashi holds that since it is an object that doesn't have a siman, there is almost no way for the owner to get it back (unless he brings witnesses that it is his). Therefore it is in the best interest of the owner that the finder would return it to whoever claims to be the owner even though he doesn't provide a siman, because that would be the only way that the rightful owner could possibly get it back. The statement of ספק הינוח לא יחזיר teaches that since the finder becomes a shomer, he is not allowed to return it unless he is sure to have found the rightful owner.

Baba Metzia 24b - Yiush after 12 months

The gemara says that when one finds something in a public area where there are rov goyim, even if a yisroel would give a siman he doesn't have to return it. But, he should return it lifnim m'shuras hadin. Just as the case where the father of Shmuel found donkeys in the midbar and returned it after 12 months do fulfill the lifnim m'shuras hadin. The gemara implies that after 12 months there is no mitzvah to return a lost object. After 12 months of what? Tosafos explains that after 12 months the finder shouldn't continue to feed the animals because the animals will eat more than their value (which the owner will have to compensate for). Therefore, for 12 months the finder should continue to feed them (and eventually charge the owner for the expense), but after 12 months he should sell them and return their value to the owner. The father of Shmuel went lifnim mishuras hadin by returning the actual donkeys even after 12 months have passed. Tosafos seems to imply that the father of Shmuel accepted upon himself the loss of feeding the animals at his own expense after the 12 months, because if he continued to charge for the food, he would be causing the looser more harm than good by keeping the actual animals. The problem is that Tosafos writes in the very next Tosafos (d.h. lifnim) that lifnim mishuras hadin doesn't demand that one suffer a loss of money - so what did the father of Shmuel do!

Rashi learns this gemara completely differently. Any object that has been lost for more than 12 months has an automatic yiush. Once the object has been lost for 12 months, the finder would be entitled to keep it, yet the father of shmuel went lifnim mishuras hadin and returned it even after 12 months passed. Rashi goes lishitaso in Brachos 58b where the gemara says a dead person is forgotten after 12 months, quoting a pasuk comparing a dead person to a lost vessel. Rashi explains:

ככלי אובד - וסתם כלי לאחר שנים עשר חדש משתכח מן הלב דיאוש בעלים לאחר שנים עשר חדש בפרק אלו מציאות דף כח ע"א מי שמצא כלי או שום מציאה חייב להכריז שלש רגלים, ואם נמצא אחר הסוכות צריך להמתין ולהכריז בפסח ובעצרת ובחג, דהיינו שנים עשר חדש ושוב א"צ להכריז

Rashi assumes that the gemara which exempts one from calling out after 3 regalim pass really means 12 months and is based on the assumption of yiush (rather than just an exemption from going through the trouble of calling it out forever). Therefore, Rashi in our sugya holds that after 12 months of it being lost one would be allowed to keep it (unless he picked it up within the 12 months and becomes a shomer on it - באיסורא אתא לידיה). The comparison of Rashi between "forgetting" someone who died, and yiush sheds some light in the understanding of what yiush is. Rashi seems to hold that yiush doesn't require a formal statement of ווי לה לחסרון כיס, rather it is just a passive position where one "forgets" the lost object no longer considering himself an owner over it. This approach is very meduyak in rashi 21b (d.h. mei'hashta) where rashi explains that according to rava we view it as if yiush is taking place now, prior to him realizing that it is lost - שהרי נפל, וכשיודע שוב אין דעתו עליו. What does Rashi mean by "וכשיודע שוב אין דעתו עליו"? He means to say that had yiush required one making an active declaration then rava would admit that it couldn't go into effect prior to him even knowing that it is lost. But yiush doesn't require an active declaration, rather it is defined as "not having da'as on it", which is a very passive stance of no longer considering oneself an owner over the object. That is why rava would allow the yiush to take effect even before the person knows that it is lost - because had he been privy to that information he wouldn't consider himself an owner over the object, which is really the definition of yi'ush (see dibros moshe he'ara #7).

Baba Metzia 22a - כלך אצל יפות

The gemara draws a distinction between the case of teruma where כלך אצל יפות implies that the owner consents to what the messenger did, and the story of mari bar isak where כלך אצל יפות was not an acceptable method of determining consent for mar zutra. The distinction is that by teruma which is a mitzvah we assume he meant what he said, but when it comes to serving the rabbonim who came to visit, we are concerned that the owner only pretended to consent out of embarrassment, but in truth did not consent. The question is that serving the rabbonim should also be considered a mitzvah of hachnosas orchim and honoring talmidei chachamim. Why isn't it considered a mitzvah like teruma where we assume the owner truly consents?

It seems that the distinction is not whether it is or isn't a mitzvah, rather the distinction is whether we have reason to believe that the owner is interested in the mitzvah and therefore consents. By teruma we are speaking in a case where he appointed the messenger to separate teruma for him. Clearly the owner is interested in performing the mitzvah of separating teruma, therefore when he gives some indication to consenting to the higher quality, we assume that he truly means it. However, in the situation where the rabbonim visited, although there is a mitvah to serve them, we have no reason to believe that mari bar isak was at all interested in doing this particular mitzvah, therefore we assume that his statement of כלך אצל יפות was said out of embarrassment and does not indicate true consent.

Baba Metzia 20b - Learning issur issues from monetary issues

The gemara makes a statement that we are not able to learn out issues that effect issur and heter, from monetary issues. This implies that the burden of proof necessary for issur must be stronger and more convincing than the burden of proof necessary for monetary issues. Tosafos asks that the exact opposite seems to be true, because we follow the majority for issur issues (even against a chazaka), yet for monetary issues we say that we don't follow rov. Do we require the proof to be stronger for monetary issues or for issur issues?

Tosafos answers that generally we assume that the proof necessary for monetary issues is greater than for issur. It is only in this specific type of issur such as marriage/divorce do we make an argument that the proof must be more substantial than by monetary issues. The precedent for this is from "mayim sh'ein la'hem sof" where we don't follow rov, rather insist on absolute evidence. Now, the concept of "mayim sh'ein la'hem sof" is only a rabbinic chumra. Therefore, on a d'oraysa level we would be able to learn all issur (including marriage issues) from monetary issues, but m'drabonon we are extra strict when it comes to marriage and divorce.

The maharatz chiyus has an exact opposite approach from Tosafos. He asks from the gemara later 27b that assumes that if the concept of returning a lost object to the owner through simanim is d'oraysa, we can also return a gett with simanim. Why don't we say that we can't learn out issur issues from monetary issues? The maharatz chiyus explains that specifically for marriage and divorce type issues which are totally under rabbinic control, do we learn issur from money because monetary issues are also entirely in the hand of beis din.

Baba Metziah 20a - Eidav b'chosamav zachin

The gemara says that when a woman says that she wrote a receipt to her husband that she received the kesuba, you can return it to him. The reason is that even if she didn't give the receipt to her husband on the date written in it, which can lead to harming someone who may have purchased her kesubah, the husband is automatically zocheh in the receipt when he receives it retroactively from the date written in it. This is based on Abaye's approach of עדיו בחותמיו זכין לו. Where does this idea of עדיו בחותמיו זכין לו come from?

Tosafos explains that the there was a takanas chachamim that the beneficiary of a contract should be zocheh in the document from the day on which it is dated, regardless of when it is delivered, so that the witnesses won't have to ensure that it is delivered on the day that it was written. The maharsha suggests that this is only necessary according to r' elazar who normally says that the eidei mesirah make the contract effective, so we need a special takanas chachamim. But, according to R' Meir who holds that the eidei chasima make the contract effective m'doraysa, of course it will be binding from the day on which it is dated (maharam shif challenges this).

Tosafos continues to question what would be with a contract that effects issur, such as a shtar to free a slave that would permit him to a bas yisroel. In a situation where the shtar was dated in nissan but only delivered in Tishrei, would we consider a bas yisroel who had relations with the "eved" between nissan and Tishrei to be passul l'kehuna since he was still an eved at the time, or can we use the eidim to make the shtar effective retroactively from nissan. Tosafos says "maybe even by a shtar that impacts issur can be effective from the time it was signed, even though the rationale for the takana isn't applicable - לא פלוג רבנן ויש כח ביד חכמים לעקור דבר מן התורה. The mishneh l'melech (zechiya u'matana 9:10) points out that Tosafos holds that even when a takanas chachamim is going to have an impact on issur, chazal would still maintain their takana.

Baba Metzia 18b - Siman muvhak

The gemara is trying to find the case where a lost gett is returned to the woman without being concerned that it is not her gett being given to her. R' Ashi makes the case to be where it is returned to her by her giving a "siman muvhak" such as identifying a hole next to a particular letter in the gett. The siman must be an excellent siman to work on something d'oraysa such as gett, because standard simanim are questionable whether they are effective d'oraysa or only d'rabonon.

The Pri Megadim in his rules of simanim and tevi'as ayin (printed at the end of his commentary on the first chelek of y.d.) says that their are 3 types of simanim:

1. Siman Muhak - There are very specific type of simanim such as a hole next to a particular letter. All agree that simanim of this type are d'oraysa and therefore work even by a gett. Furthermore, this type of siman works even to take away from a chazaka, just as it removes a woman from a status of eishes ish. Although this would seem obvious from our gemara, it isn't. The pri megadim raises the possibility that on a d'oraysa level we aren't concerned that this gett belongs to someone else (even if there are husbands with the same names and the caravans are common), the entire concern of it belonging to someone else is only d'rabonon. Therefore, it could be that although siman muvhak does not have the power to remove from a chazaka, it works since the entire concern of the gett belonging to someone else is only d'rabonon.

2. Standard siman - This is a machlokes whether it is d'oraysa or d'rabonon. Rambam paskens that it is d'oraysa based on the gemara later 28a. If we assume a standard siman is d'oraysa, why can't we rely on it to testify for a woman that her husband died? Pri Megadim explains that even if it is d'oraysa it isn't strong enough to take out of a chazaka, therefore it only works d'oraysa by a lost object, but not to allow a woman to remarry.

3. Poor simanim - This group is a type of siman that is barely recognized as a siman even on a d'rabonon level. It is only in the context of a low level issur d'rabonon such as meat that has been left unattended, do we rely on this type of siman to confirm that it is the same meat that was left originally.

Baba Metzia 16a - Purchasing with a loan

The gemara says that if shimon stole a field from reuven and sold it to levi, if afterward shimon would purchase the field from reuven to maintain his sale to levi, levi would automatically own it without any kinyan. The gemara tries to understand what exactly would create the kinyan since the original contract is completely worthless. It is clear from the gemara that a kinyan made with a contract is effective by the seller handing it to the buyer. If at the time it was handed to the buyer it was a worthless document because the seller didn't own it at the time, it cannot go into effect afterwards just by being in the hand of the buyer.

Tosafos raises a question, why can't the money that was given by levi to shimon originally to acquire the field make the kinyan now that shimon purchased the field and now has rights to sell it. Tosafos says that this would be a problem of "mekadesh b'milveh". Just as one cannot marry a woman with a loan, one cannot purchase a piece of property using a loan. It seems to me that this answer only works according to Shmuel who holds that we view the money that levi paid to shimon as a loan, but according to Rav who views it as a pikadon, levi should be able to use it as a kinyan on the property. Does Tosafos answer only work in Shmuel?

Another point is that Tosafos explains that if a loan can create a kinyan, the money that levi paid shimon originally for the field would immediately be effective as money to acquire the field without having to speak anything out. Whereas, using the "hana'ah" of being mochel on a loan to create a kinyan, levi would have to speak out that he is being mochel the money to shimon and making a kinyan on the field with the hana'ah that shimon would receive. Therefore, a difference between acquiring with "a loan" and acquiring with "hana'ah of mechila on a loan" is that the latter must be spoken out explicitly.

Baba Metziah 13 - Rei'usa in a lost shtar

It is hard to find time for extra he'aros on today's daf since the pashut p'shat is so difficult, but here is something:

The Ketzos HaChoshen (65:9) points to an interesting contradiction in Rashi regarding the problem with a shtar that has been lost being suspect to being forged or paid. Rashi on 7b in the case of a shtar that ends up in the hands of a third party, writes that it shouldn't be returned to the borrower or lender unless there are witnesses to verify that it fell from the lender. Rashi holds that the reason for not returning the contract is that we have no idea if it is a valid contract and/or if it has already been collected. But, if we see the contract fall from the lender we would return it to him which would give him the ability to collect with it. But in our gemara we say that when the shtar is lost there is an automatic "rei'usa" in the shtar, so how can we return it to the lender to collect with? Rashi must be holding that we would normally be able to assume that the fact that the contract wasn't destroyed, it must have fallen from the lender. However, since it was lost it creates a rei'usa that forces us to be concerned that it fell from the borrower - therefore, if we have witnesses that it fell from the lender we can return it him.

However, Rashi 12b seems to say that when a shtar is lost it is a rei'usa in the entire validity of the contract based on the logic that if it would be valid he wouldn't have lost it. This would force us to suspect that even if we knew it fell from the lender we shouldn't return it to him. Based on this approach, if the lender would find it himself he can collect with it, but once it fell from him we would never return it to him even if we know through witnesses that it fell from him.

Tosafos 13b asks, why can't we return a contract that falls to the lender even if the borrower claims that it is forged - since the lender can't collect without being mekayem the signatures, if he manages to do so that will prove the validity of the contract? Tosafos answers that since the borrower is claiming that it was forged and their is a rei'usa that it fell, we don't trust the kiyum of the signatures because he may have done such a good forgery job that he fools the witnesses into thinking that it is actually their signatures. However, Tosafos is not sure about using the contract to collect from the borrower himself - maybe the kiyum would allow the lender to collect from the borrower himself because he has the ability to bring witnesses to contradict the witnesses of the lender. In the process of the discussion, Tosafos writes: 

אפילו יקיימנו יש לחוש שמא מזוייף הוא ולכך קאמר לא יחזיר פן יטרוף כשתשתכח הנפילה

This would imply that so long as we know that it fell, even if it somehow ends up in the hand of the lender, he would not be allowed to collect using this contract. If it is assur for the lender to collect using this contract, we would certainly not return it to him even if there are witnesses that it dropped from him (which is against rashi on 7b).

Baba Metzia 12a - Who gets to keep the babysitting money?

The mishna says that a lost object that is found by a child goes to his father. The gemara says that Shmuel and R' Yochanan disagree about who is a "katan". Shmuel holds that we are speaking of a child below bar mitzvah (Tosafos 12b), therefore the rationale for his lost object going to his father is that when he originally picks it up, he does so for his father [It is not so clear how a child is able to be zocheh in the object by picking it up, for his father. Hagahos Mordechai seems to say that only after the father actually receives it do we say that it belongs to the father. However, the Ritva explicitly writes (as implied by rashi) that the father is zocheh in it even prior to it coming into his hands. R' Yochanan disagrees about the definition of a "katan". He holds that age is not the issue. Anyone who is self sufficient is considered an adult, but the object found by any child who relies on his parent for support belongs to the father. The SM"A (270:2) quotes himself in the drisha where he explains that the rabbonon instituted this as a means of compensation and hakaras hatov for the support that they are providing without being obligated - ונראה ישר לחכמים לשלם הטוב לעושה עמו טוב, שמזין אותו אע"פ שאינו חייב לפרנסו כי אם עד ו' שנים

However, Tosafos points out that chazal only instituted this by a parent who supports a child to avoid an concern of animosity building up, but one who supports an orphan is not entitled to the objects that he finds (as paskened in the Rama 270:2). The rationale is that even if one gets annoyed and stops supporting the orphan when he realizes that he isn't entitled to his findings, we aren't so concerned because someone else is likely to feel bad for him and pick it up, which is no the case when his parents are alive.

Regarding a child who works and earns money, the Rama rules that the father is also entitled to that money due to the same takana. However, R' Akiva Eiger quotes those who disagree. The Machaneh Ephraim (zechiya 3) quotes a machlokes rashi and Ritva in Baba Metziah 92b. Rashi holds that it has the same din as the metziah which goes to the father, but the Ritvah says that chazal didn't give the father ma'aseh yadayim of his son. In regard to a daughter, the father has rights to her metziah even if she is not being supported by him (until she is a bogeres - 12 1/2). Rashi holds this is a d'oraysa, but Tosafos holds that it is a d'rabonon to avoid animosity so that he doesn't marry her off to a degenerate. Presumabely, her earnings would also be pending on the same machlokes.

Being that it is a major machlokes who is entitled to the earnings of a child, it would seem that if the child is paid directly by the employer he or she can say that they hold like the opinion who says that they can keep it. But if the employer pays the father then he can also say he holds like the opinions who say that he is entitled to her earning.

Baba Metzia 12a - Kinyan Chatzer

The gemara concludes that a chatzer can either work as a "yad" or as a "shliach". There are many variables as to what may be needed for the chatzer to work: 1. zechus, not a chov. 2. a protected chatzer. 3. standing next to it. 4. da'as acheres being makneh the object.

These are the rules (as recorded in the Rosh):

To acquire a gett which can be given against her will, the chatzer cannot serve as a shli'ach only as a yad, therefore we require her to be standing next to the chatzer AND for it to be a protected area (chatzer mishtameres) which are both characteristics of a yad. Why is this true? Why can't a woman "appoint" the chatzer to serve as her shliach just as she can appoint a shliach to receive her gett? It seems that the chatzer which is inanimate object cannot be "appointed" as a shliach. In a case where it is clear to all that the receiver would want the chatzer to serve as a shliach (such as a matana or metziah where it is a zechus and therefore there is an "anan sahadi" that he wants it), it can be considered a shliach. But in a case where the receiver wouldn't always want it to serve as a shliach such as by a gett which is a chov, it can never be a shliach. 

But to acquire a gift or lost object, the chatzer can either be functioning as a yad or a shliach, depending on the circumstances. When it is functioning as a shliach, the receiver doesn't have to be standing next to it, just as a live shliach can function as an  agent in the absence of the owner. This is true so long as the chatzer is protected, but if the chatzer isn't protected, then he must either be standing there (to create a protected chatzer or work as a yad) or have a da'as acheres being makneh the object. Therefore, to acquire a lost object that does not have anyone being makneh it to him, it must be in a protected field, or he must be standing there (so it is considered protected or serves as a yad). Why does the chatzer have to be protected to serve as a shliach? The Rosh explains that one will generally only choose a shliach who is "protected" so that the object will be safe in his hand, therefore a chatzeir that is unprotected cannot serve as a shliach since we no longer have the "anan sahadi" that one will ALWAYS want it to be his shliach. [When the field isn't protected but he is standing there, the reason that it works is different for a man and woman - for a woman it works as a yad, but for a man chatzer cannot be a yad therefore it works as a shliach (since he can easily reach the objects it is like they are in his hand)]. 

BUT for a matana that has an advantage of  da'as acheres being makneh it, the chatzer can serve as a shliach even if it is unprotected. Why does the da'as acheres compensate for the chatzer being protected? The Rosh explains:

אבל במתנה מסכמת דעת המקבל בכל מקום שיתנהו הנותן שיזכה לו המקום שיזכה לו המקום ושמירת הנותן חשובה לו כשמירתו The language of the Rosh is not so clear, but he seems to say that when there is a "giver", the receiver trusts the giver to protect the object and therefore the chatzer can serve as a shliach even though the field is not protected.

Baba Metzia 10b - Shliach L'dvar Aveira

The gemara explains that the parameters of when we say that one can be a shliach for an aveira to make the sender liable for the action, is either that the shliach is not a bar chiyuva in this prohibition, or that the shliach has no ability to choose not to do it. Both approaches rely on the fact that אין שליח לדבר עבירה is predicated in the premise that rashi points out - דאמרינן ליה דברי הרב ודברי התלמיד דברי מי שומעין ולא היה לו לעשות. Meaning, when the shliach is a bar chiyuva and has the choice to do it or not to do it, the argument can be made that he shouldn't have done it and therefore takes responsibility (the sm"a that i mentioned in the previous post seems to look at it from the perspective of the sender who has an excuse to say that he never expected the shliach to follow through with it). But in a case where the shliach is no a bar chiyuva, there is no reason for him to abstain from doing it, so the sender cannot make the argument that the shliach should not have done it. Certainly, if the shliach is forced to do it and does not make his own choice, he is merely an extension of the arm of the sender so that the sender will be chayev.

Tosafos is bothered by why we consider a yisroel who is acting as a shliach of a kohen to be mekadesh a divorcee, as one who is not a bar chiyuva. Although the yisroel is not included in the prohibition of being mekadesh a gerusha, he is certainly in violation of lifnei iver by assisting the kohen in performing the kiddushin and should be regarded as a bar chiyuva (which would result in  ein shliach l'dvar aveira making it that the yisroel is in violation rather than the kohen). Tosafos rejects this concern that we don't determine if the shliach is a bar chiyuva by whether he is doing an issur, rather we determine it by whether the issur that he is doing for the kohen is applicable to him (and there isn't any issur on him to marry a divorcee). The Nodeh B'yehuda (quoted by maharatz chiyus) points out that Tosafos could have simply rejected the issur of lifnei iver causing the shliach to be considered a bar chiyuva, because it is not "two sides of a river" (meaning that the kohen could have done the issur without the yisroel), so it is only an issur d'rabonon of assisting one in doing an aveira, and the mishneh l'melech (hilchos rotzeiach) holds that on an issur d'rabonon we hold יש שליח לדבר עבירה. From the fact that Tosafos doesn't say this implies that Tosafos holds that even on an issur d'rabonon we hold ein shliach l'dvar aveira.

I discussed this issue previously http://hearos.blogspot.com/2009/02/baba-kama-51a-ein-shliach-ldvar-aveira.html. The mishneh l'melech proves that we say ein shliach l'dvar aveira even on an issur d'rabonon from rashi in baba kama who says that we say ein shliach l'dvar aveira on the digging a pit in the public domain even though it is only a rabbinic prohibition of destroying public property. However, the meshech chochma (kedoshim) says that the issur of digging a bor in reshus harabim is the prohibition of lifnei iver, which is d'oraysa, thereby disproving the proof of the mishneh l'melech.

Baba Metzia 8a - Partners that steal

The gemara says that if partners steal they are both chayev, but if reuven asks shimon to steal for him, only shimon is chayev. Rashi explains that the case of partners stealisn is when one partner does the act of geneiva for both. Since he does it on behalf of both of them, they are both chayev. Tosafos disagrees because we would only says that one can be a shliach l'dvar aveira on the act of shechita to be chayev 4 or 5, but on the act of geneiva even if reuven and shimon are partners, we would not say that shimon can serve as reuven's shliach to make reuven chayev for geneiva. Therefore, the only case that reuven would be chayev is when he commits the act of geneiva together with Shimon.

The Maharatz Chiyus points out that this is difficult even according to Tosafos. Why would we say that when reuven and shimon pick it up together - מיגו דזכי לנפשיה זכי נמי לחבריה. Even when they steal it together, since we have a concept of אין שליח לדבר עבירה, reuven is not able to serve as shimon's agent to steal it, and shimon cannot serve as reuven's agent, so it should be considered from each one's perspective as if the other half of the talis is still lying on the ground and they were never koneh it? The mahartz chiyus explains based on the sm"a (c.m. 182) who says that אין שליח לדבר עבירה is based on the idea that the sender doesn't really expect the shliach to do the issur, because he knows that the shliach should listen to Hashem rather than him. This only makes sense in a case where the sender maintains his innocence, but in our case where both reuven and shimon are doing an act of stealing, they aren't innocent and cannot claim that they didn't expect the other person to follow through with the shlichus of an aveira. Therefore, in the case where reuven and shimon are doing the aveira together we say יש שליח לדבר עבירה and each one serves as the agent of the other to help him be koneh.