1) THE DIFFERENCE BETWEEN A "KASHYA" AND A "TEYUVTA"
QUESTIONS: Rav Shizbi states that a Bris Milah not be performed on a Tumtum on Shabbos, because the verse which permits Milah on Shabbos specifically says that the child must be a Zachar, a fully-recognizable male, from the time he is born. Similarly, Rav Sheravya states that a woman who gives birth to a Tumtum is not Tamei with Tum'as Leidah, since the verse implies that the child must be a fully-recognizable male (or female) at the time of birth in order for the mother to become Tamei with Tum'as Leidah.
The Gemara challenges both opinions from the Mishnah in Nidah (28a) which says that a woman who gives birth to a stillborn Tumtum is Tamei out of doubt for 14 days as if she gave birth to a female, and afterwards she has only 26 days of Taharah (until 40 days after her birth) as if she gave birth to a male. This clearly contradicts Rav Sheravya's statement, who rules leniently and says that the birth of a Tumtum does not make the mother Tamei at all, and thus the Gemara says "Teyuvta."
The Gemara suggests that it does not contradict Rav Shizbi's assertion. Perhaps the Mishnah in Nidah means that the woman must conduct herself stringently, out of doubt whether or not the verse indeed excludes the birth of a Tumtum from the law of Tum'as Leidah. Rav Shizbi, too, requires that one be stringent and not perform the Milah of a Tumtum on Shabbos, out of doubt whether or not the verse excludes a Tumtum from the allowance to perform Milah on Shabbos.
The Gemara refutes this answer and says that if the Mishnah in Nidah means that the woman should conduct herself stringently out of doubt whether or not the birth of a Tumtum is considered a birth, then it should also require her to conduct herself like a Nidah out of doubt that perhaps a Tumtum is excluded altogether from Tum'as Leidah. It must be that the Mishnah in Nidah maintains that the birth of a Tumtum definitely makes the mother Tamei, and the only doubt is whether the Tumtum is considered a male or a female. The Gemara calls its refutation of the view of Rav Shizbi a "Kashya."
(a) The RASHBAM writes that although the Gemara concludes with a "Kashya" on Rav Shizbi, the Halachah still may follow his view. This is because the Gemara does not conclude its challenge with the word "Teyuvta." Indeed, the RIF rules like Rav Shizbi for this reason (see BEIS YOSEF YD 266, and PILPULA CHARIFTA #200).
However, the Rashbam seems to contradict his comments. Earlier (52b, DH u'Pasak), the Rashbam cites the opinion of RABEINU CHANANEL who says that whenever the Gemara concludes a challenge with the word "Teyuvta," that opinion is considered refuted entirely, but when the Gemara concludes a challenge with the word "Kashya," the opinion that it challenged is not refuted and it is possible to find an answer to the Gemara's challenge and to rule in accordance with that opinion. The Rashbam there disagrees with Rabeinu Chananel and maintains that there is no essential difference between these two expressions. The only difference is that when the challenge is from a Tana, the Gemara uses the word "Teyuvta," and when the challenge is from an Amora, the Gemara uses the word "Kashya." The Rashbam here, however, agrees with Rabeinu Chananel's explanation!
(b) There also appears to be a contradiction in the words of the ROSH (8:16). The Rosh asks how can the Rif rule in accordance with Rav Shizbi after the Gemara refutes his opinion from a Mishnah. The Rosh earlier (3:58), however, rules in accordance with the view of Shmuel, even though the Gemara there (52b) refutes Shmuel's opinion and concludes with the word "Kashya." Why, then, does the Rosh question the Rif's ruling in the case of the Gemara here?
Similarly, the RAMBAM does not rule like Rav Shizbi, presumably because his opinion is refuted and the Gemara concludes with the word "Kashya." However, the Rambam (Hilchos Nachalos 9:8) does rule like Shmuel, even though the Gemara refutes his opinion and concludes "Kashya."
(a) The NODA B'YEHUDAH (YD 2:163) answers the contradiction in the words of the Rashbam by explaining that when the challenge is from an Amora and the Gemara concludes "Kashya" as in the case of the Gemara earlier (52b), there is no indication that the position being refuted can be answered. In the case of the Gemara here, however, the challenge on Rav Shizbi is from a Mishnah. When the challenge is from a Mishnah, the Gemara should conclude "Teyuvta." Since the Gemara instead concludes "Kashya," it is hinting that there is an answer to the question and the Halachah may follow Rav Shizbi.
(b) The questions on the Rosh and the Rambam may be answered if the Rosh and Rambam concur with the view of TOSFOS in Moed Katan (2b, DH Chayav). Tosfos writes that the Gemara concludes "Kashya" only when the question is from a Tana (the opposite of the Rashbam's approach according to the Noda b'Yehudah). Accordingly, when the question is from an Amora and the Gemara concludes "Kashya," that word is an error, since one Amora may argue with another Amora. Therefore, the Gemara earlier (52b) which challenges Shmuel's opinion from an Amora should not have concluded with the word "Kashya"; that word in the text of the Gemara is a mistake, and the Halachah indeed may follow the view of Shmuel. In the Gemara here, the challenge is from a Tana, and thus the Gemara appropriately concludes "Kashya," refuting the opinion of Rav Shizbi. (Y. MARCUS)
2) RETRACTING ONE'S STATEMENT CONCERNING A SON OR DAUGHTER
QUESTION: The Gemara says that a father is believed to say that his son is a Bechor and, similarly, to say that his son is the son of a divorcee (thereby disqualifying him from serving as a Kohen). A father is also believed to say that his son is an Eved. Nevertheless, if a man says that the person accompanying him is an Eved and then says that he is his son, he is believed, and the son does not have the status of an Eved. This is because he may explain his original statement (that his son is an Eved) by saying that he merely meant that he son serves him as diligently as an Eved serves his master. It appears that even though the father was believed when he said that his son is an Eved, he now may explain himself and retract his original statement.
This Gemara seems to contradict the view of the TESHUVOS MAHARAN LEV (1:43). The Mishnah in Kidushin (64a) teaches that a father is believed to say that he married off his daughter, as long as his daughter has not yet reached the age of a Bogeres (twelve and a half years old). The Maharan Lev cites the opinion of the Chachamim of Provence who rule that once the father says that his daughter is married, he cannot retract his words, even if gives an excuse for why he said that she was married.
The Gemara here, though, says that a father may retract his original statement when he provides a valid excuse for why he said it. Why, when a father says that his daughter was married, can he not retract his statement, according to the Maharan Lev?
ANSWER: The SHEV SHEMAITSA (6:8) answers that the Chachamim of Provence were referring only to a case in which the second statement is a complete retraction of the first statement, such as when the father first said that his daughter was married and now completely denies it. In the case of the Gemara here, however, the father is only explaining the meaning of his first statement, but he is not denying its truth. Therefore, he is believed. (Y. MARCUS)