1) IS A "CHAVER" SUSPECTED OF INTENTIONALLY CAUSING A "MUM"
OPINIONS: The Gemara relates that Rebbi Tzadok had a Bechor that became blemished when its lip was cut as it ate barley from a basket of peeled willow branches (with sharp edges) that Rebbi Tzadok had prepared for it. Rebbi Tzadok asked whether only a Kohen Am ha'Aretz is not trusted to testify that he did not intentionally inflict a Mum on his Bechor, but a Kohen Chaver is trusted, or whether even a Kohen Chaver is not trusted.
Rebbi Tzadok brought his question to Rebbi Yehoshua, who answered that a Chaver is believed to say that the Mum came about naturally, and he is not suspected of intentionally causing the animal to become blemished. Rebbi Tzadok then brought his question to Raban Gamliel, the Nasi, who answered that a Chaver is not believed, just as an Am ha'Aretz is not believed, and in order to eat the Bechor the Kohen must bring proof that he did not intentionally inflict the Mum.
When Raban Gamliel challenged Rebbi Yehoshua in public about his ruling, Rebbi Yehoshua declared that he agreed with Raban Gamliel's ruling.
Did Rebbi Yehoshua actually retract his opinion?
(a) RASHI (DH Hei'ach) explains that Rebbi Yehoshua indeed retracted his original ruling. TOSFOS (35b, DH v'Chi) points out that Rashi's explanation is supported by the Gemara earlier (35b) in which Rav Nachman asks, "If a Yisrael is just as untrustworthy as a Kohen with regard to Bechor, then who will ever be trusted as a witness to permit a Yisrael to eat his Safek Bechor?" Why does Rav Nachman not answer simply that only one who is not an Am ha'Aretz is trusted, while a Chaver is trusted, as Rebbi Yehoshua stated? Apparently, Rav Nachman understood that Rebbi Yehoshua retracted his ruling.
(b) TOSFOS (DH Hei'ach, and 35b, DH v'Chi) explains that Rebbi Yehoshua did not retract his original ruling. He declared that he agreed with Raban Gamliel in public only out of deference for the Nasi. Tosfos proves this from the Gemara in Berachos (27b) which records a similar incident that occurred with regard to a different dispute, and the Gemara there rules like Rebbi Yehoshua.

36b----------------------------------------36b

2) ONE WHO GAVE A BECHOR TO A KOHEN "WHEN HE WAS SMALL"
QUESTION: Rebbi Yirmeyah bar Aba taught that a Yisrael is believed to say, "I gave this Bechor to a Kohen when it already had a Mum." The Gemara asks that it is obvious that the Yisrael is believed, since there is no reason for him to lie about the Mum.
The Gemara answers that Rebbi Yirmeyah bar Aba was teaching that a Yisrael is believed even in a case in which "he was small and became big."
RABEINU GERSHOM explains that this means that the Yisrael is believed to testify now as an adult about what he did when he was a minor (when he gave the Bechor to the Kohen).
RASHI (DH b'Katan) explains that the Yisrael is believed to say that he recognizes the animal now even though the animal was small when he gave it to the Kohen and now it is large.
Why does Rashi not explain the Gemara as Rabeinu Gershom explains it?
ANSWERS:
(a) The NEZER HA'KODESH suggests that perhaps Rashi maintains that a minor does not have the Halachic prerogative to give a Bechor to a Kohen. When the Torah requires that something be "given" ("Nesinah"), the act of giving must be done by an adult, because only an adult has the ability to effect a transaction of "giving." (See KETZOS HA'CHOSHEN 243.)
(b) The Gemara in Kesuvos (28b) mentions several cases in which a person is believed to testify as an adult about what he saw as a child. The Gemara explains that such testimony is accepted only in cases in which the testimony is relevant mid'Rabanan, but not when the testimony involves a matter which is mid'Oraisa. Perhaps Rashi does not accept Rabeinu Gershom's explanation because the testimony that a Bechor had a Mum is relevant mid'Oraisa; mid'Oraisa, the Kohen may eat the Bechor only if we know for certain that the Kohen did not inflict the Mum in the Bechor himself. Since the testimony involves a matter which is mid'Oraisa, the Yisrael may not testify about a Mum that he saw when he was a minor.
Accordingly, Rashi is consistent with his opinion expressed earlier that a Bechor in which a Mum was intentionally inflicted may not be eaten mid'Oraisa (see Insights to Bechoros 34:5). Rabeinu Gershom, however, must maintain that it is prohibited only mid'Rabanan (as Tosfos proves; see Insights to Bechoros 34:3). (M. KORNFELD)
3) ALL ARE BELIEVED TO TESTIFY ABOUT A "MUM" OF "MA'ASER BEHEMAH"
QUESTION: The Mishnah teaches that everyone is trusted to testify about a Mum found on an animal of Ma'aser Behemah (whether it was intentionally inflicted or it came about naturally).
RASHI (DH ha'Kol) explains that this Mishnah refers not to an animal that is definitely Ma'aser, but to an animal that is Safek Ma'aser. Why does Rashi explain the Mishnah in such a manner?
ANSWER: The MAHARIT ALGAZI discusses whether a Kohen is trusted, during the times of the Beis ha'Mikdash, to say that he did not inflict a Mum on his Bechor. Perhaps a Kohen is suspected of inflicting the Mum himself only when the Beis ha'Mikdash is not standing. When there is no Beis ha'Mikdash, the Kohen must take care of any unblemished Bechor until it dies or becomes blemished, and this involves considerable effort and expense. The Kohen prefers that his animal become blemished so that he can slaughter it and eat it, and thus we suspect that he might blemish it himself. In contrast, when the Beis ha'Mikdash is standing, the Kohen is able to offer any unblemished Bechor as a Korban immediately, with little effort and expense, and thus perhaps we do not suspect the Kohen of intentionally inflicting a Mum on the Bechor.
The Maharit Algazi proves from the words of Rashi here that we suspect a Kohen only when there is no Beis ha'Mikdash. Rashi explains that the Mishnah is discussing specifically an animal that is Safek Ma'aser, since that is the only type of Ma'aser that is not brought as an offering (see 53a-b). It is only in such a case that one might have thought that a Kohen is not trusted to testify about the Mum, since the Kohen must take care of the animal and cannot offer it as a Korban. This implies that a Kohen is trusted to testify about a Bechor or definite Ma'aser Behemah that could be offered in the Beis ha'Mikdash.
The SHE'ELAS DAVID (Rav Dovid'l Karliner) notes that Rashi expresses this view in Sanhedrin (30b, DH b'Edus), where he writes explicitly that a Kohen is not believed to testify about blemishes of a Bechor "bi'Zeman ha'Zeh."
4) TESTIFYING ABOUT A "MUM" OUTSIDE OF ERETZ YISRAEL
QUESTION: The Mishnah teaches that a Bechor whose eye was blinded, foreleg was cut off, or whose hind leg was broken, may be slaughtered if three members of the "Keneses" ("assembly") agree that the wound constitutes a Mum. RASHI explains that the blemishes mentioned in the Mishnah are blemishes that are obvious to all as actual Mumim ("Mum Muvhak"). Rashi also writes that the three members of the Keneses are believed even if they are not experts.
The Gemara quotes Rebbi Simla'i and Rebbi Yehudah Nesi'ah who said in the name of Rebbi Yehoshua ben Levi that a Bechor with a Mum in Chutz la'Aretz may be permitted by three laymen. Rava adds that they may permit only "Mumin Muvhakin," obvious blemishes. The Gemara asks what new Halachah Rava is teaching, since the Mishnah already implies that the laymen may permit only obvious blemishes. The Gemara answers that from the Mishnah alone one might have thought that in Chutz la'Aretz, the three laymen may permit even blemishes that are not obvious; the reason why the Mishnah mentions obvious blemishes is that it wants to teach that even when the animal has an obvious Mum, Rebbi Yosi (in the end of the Mishnah) requires that only a Mumcheh (expert) permit the animal. Rava therefore teaches that in Chutz la'Aretz, the laymen may permit only obvious blemishes, and that is the intention of the Mishnah as well.
The Gemara's question could have been answered differently. Perhaps Rava needs to teach that three laymen may permit a Bechor in Chutz la'Aretz only when its Mum is a Mum Muvhak because one might have thought that the Mishnah is teaching the Halachah that is relevant in Eretz Yisrael during the times of the Beis ha'Mikdash. Since an unblemished Bechor is offered on the Mizbe'ach in the Beis ha'Mikdash, perhaps the Mishnah permits the three laymen to pronounce a Mum only when it is an obvious Mum, in order for the Mizbe'ach not to lose Korbanos that should be offered. In contrast, in Chutz la'Aretz -- where the animal anyway cannot be offered as a Korban -- one might have thought that three laymen may permit a Bechor even when its Mum is not obvious. Therefore, it is necessary for Rava to teach that even in Chutz la'Aretz three laymen may permit only obvious Mumim.
Why does the Gemara not give this answer?
ANSWER: The MAHARIT ALGAZI answers that it must be that the Mishnayos here are discussing the laws of Bechor in Chutz la'Aretz, in a time when there is no Beis ha'Mikdash. He cites RABEINU GERSHOM who proves this from the account in the Mishnah earlier (35a) of the old sheep with long hair. If the Mishnah is discussing Eretz Yisrael during the times of the Beis ha'Mikdash, the sheep certainly would not have been left to age, but rather it would have been offered as a Korban on the Mizbe'ach.
This is also the opinion of TOSFOS (DH Hitarta) who notes that the ruling of the Amora'im in the Gemara here that three laymen may permit a Bechor in Chutz la'Aretz cannot be derived from the law of the Mishnah, because perhaps the Mishnah is discussing Chutz la'Aretz after the Churban of the Beis ha'Mikdash. The Amora'im, in contrast, are discussing Chutz la'Aretz during the time that the Beis ha'Mikdash is standing in Yerushalayim. Therefore, from the Mishnah alone, which discusses the period when the Beis ha'Mikdash is not standing, one might have thought that when the Beis ha'Mikdash is standing, three laymen may not permit a Bechor in Chutz la'Aretz because of a Gezeirah lest they permit a Bechor in Eretz Yisrael. The Maharit Algazi points out that Tosfos understands that since the Mishnah earlier (35a) specifically refers to Chutz la'Aretz, presumably the rest of the Mishnayos in this Perek refer to the laws in Eretz Yisrael.
The Maharit Algazi adds that even though the Mishnah earlier (on this Daf) states that everyone is trusted to testify about a Mum found on an animal of Ma'aser Behemah, which implies that the Mishnah is discussing the period when the Beis ha'Mikdash is standing (because the Chachamim suspended the law of Ma'aser Behemah when the Beis ha'Mikdash is not standing; see 53a-b), nevertheless Tosfos in Avodah Zarah (13a, end of DH Ein Makdishin) writes that the Chachamim did not suspend the law of Ma'aser Behemah immediately after the Churban, but rather only after some time had passed. Therefore, it could be that the Mishnah that says that everyone is trusted with regard to Ma'aser Behemah refers to the period after the Churban but before the law of Ma'aser Behemah was suspended. (D. BLOOM)
5) THE DIFFERENCE BETWEEN A "CHACHAM" AND A "MUMCHEH"
QUESTION: Rav Chiya bar Amram (36b) teaches that three laymen may permit a Bechor based on its Mum in a place where there is no "Mumcheh," and that three laymen may annul a Neder in a place where there is no "Chacham." Why does he use the word "Mumcheh" with regard to permitting a Bechor, and the word "Chacham" with regard to annulling a Neder?
ANSWERS:
(a) TOSFOS (DH b'Makom) explains that a Mumcheh is a person who is known for his vast Torah knowledge and expertise with regard to Mumim. "Mumcheh" implies that he has considerable practical experience in examining blemishes of animals. The word "Chacham" refers primary to a person with vast Torah knowledge. In order to annul vows, the primary prerequisite is that he be a Torah scholar. In order to permit Bechoros, he also must have considerable practical experience (in order to recognize which Mum will heal and which will not). (BI'UR HA'GRA YD 309:5)
(b) The RAMBAM (Hilchos Bechoros 3:2) explains that a Mumcheh is a person who received permission from the Nasi of Eretz Yisrael to issue rulings about a Bechor. In contrast, a Chacham does not need permission from the Nasi in order to annul vows.
HALACHAH: Everyone agrees that nowadays no one is considered a Mumcheh to permit Bechoros by himself (Tosfos DH Pesak, SHULCHAN ARUCH YD 309:2). The Gemara teaches that in order for three laymen (who are not experts) to permit a Bechor based on its Mum, three basic conditions must be fulfilled: they may permit a Bechor only in Chutz la'Aretz; the Mum must be a very obvious blemish ("Mum Muvhak"); and there must be no Mumcheh available in the town who can permit Bechoros by himself (this condition is automatically fulfilled according to the ruling of the Shulchan Aruch that no one has the status of a Mumcheh today).

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