1) THE OPINION OF REISH LAKISH IN A CASE OF REBBI SHIMON
QUESTION: Reish Lakish (10b) maintains that when a man ("Reuven") dies and his wives fall to Yibum, when one of his surviving brothers ("Shimon") performs Chalitzah with one of the Tzaros, all of the other brothers are prohibited to all of the Tzaros with an Isur Kares (the Isur of "Eshes Ach"). Only the wife and the brother who performed Chalitzah are not prohibited to each other with an Isur Kares, but rather with an ordinary Lav (the Isur of "Lo Yivneh").
The Gemara challenges the view of Reish Lakish from a Beraisa. The Beraisa states that if Shimon performs Chalitzah with the Yevamah, marries her, and then dies, the other brothers are obligated to perform Chalitzah with her. According to Reish Lakish, however, there should be no obligation of Chalitzah because the woman is forbidden to the brothers with an Isur Kares.
Rav Ashi (11a) answers that the Beraisa follows the opinion of Rebbi Shimon and refers to a different case from the one which Reish Lakish discusses: Reuven dies, and Shimon performs Chalitzah with Reuven's wife. Then, new brothers are born. Since those new brothers were not alive when Shimon performed Chalitzah, no Isur took effect upon them when Shimon did Chalitzah. Thus, after Shimon marries the woman and dies, they are not prohibited to his wife and they must perform Chalitzah.
RASHI (DH u'Metaretz Lah and DH ha'Yiludim) implies that according to Rebbi Shimon, if a new brother ("Levi") is born after Shimon performs Chalitzah but before he marries the woman, the new brother is forbidden to the woman because of "Eshes Achiv she'Lo Hayah b'Olamo" -- she was marred to Reuven before he was born. Only if Levi is born after Shimon marries her is he permitted to perform Yibum with her when Shimon dies, because in that situation the prohibition of "Eshes Achiv she'Lo Hayah b'Olamo" does not apply to Levi (since he was in the world when Shimon was married). The RASHBA and ME'IRI write this explicitly.
Rebbi Shimon rules that when a new brother ("Levi") is born after Shimon performs Yibum, the woman is no longer considered "Eshes Achiv she'Lo Hayah b'Olamo" and Levi may perform Yibum with her when Shimon dies. If this is the view of Rebbi Shimon, why does he not say the same thing in a case in which Levi is born after Shimon performs Chalitzah with the woman (and then marries her)? Chalitzah accomplishes the same effect as Yibum -- it ends the Zikah from the wife's marriage to the first husband! Why does Rashi assume that Rebbi Shimon still considers the woman an "Eshes Achiv she'Lo Hayah b'Olamo" even in a case in which Levi is born after the Zikah has ended (through Chalitzah) but before Shimon marries the woman?
What is Rashi's source for this assumption? What logic is there to say that Shimon's marriage to his Chalutzah changes the status of the brother born after the marriage, and it is not the same as his status had he been born after Shimon performed Yibum with her? Why should the marriage make any difference if it has nothing to do with Yibum?
ANSWER: According to Reish Lakish who maintains that the other brothers are forbidden to all of the Tzaros with an Isur Kares, how is a case of a "Nefilah Sheniyah" possible? (The case of "Nefilah Sheniyah" is when Reuven died and one of the surviving brothers, Shimon, performed Yibum with one of Reuven's wives, and then Shimon died, in which case the surviving brothers have an obligation to do Yibum with the woman.) All of the brothers are forbidden to Shimon's wife (the Yevamah) because she is their "Eshes Ach" (since she was married to Reuven)!
The answer to this question may be found in the words of RASHI later (20a, DH Achoso; see also Tosfos DH Hai) who discusses Rebbi Shimon's opinion that when the new brother was born after Shimon did Yibum, he is permitted to do Yibum with Shimon's wife when Shimon dies. He explains that Rebbi Shimon's logic is that there is no question that Shimon himself was permitted to the woman, because he married her through Yibum. Since Shimon's wife falls to Levi through the medium of Shimon (since she was Shimon's wife), Levi has the same allowance to marry her as Shimon had. That is, Levi in a sense "inherits" Shimon's allowance to marry her.
This explains why the woman -- after the second Nefilah (when Shimon dies after he performed Yibum with Reuven's wife) -- is permitted to the brothers according to Reish Lakish. Although they are forbidden to the Yevamah with an Isur Kares, now that they "receive" the Yevamah "through" Shimon, they also receive Shimon's allowance to marry her.
Why, though, does Reish Lakish say that if Shimon performed Chalitzah and then married the woman, all of the other brothers are forbidden to her with an Isur Kares and may not perform Yibum with her if Shimon dies? Reish Lakish should say that when Shimon dies, the brothers inherit Shimon's allowance to marry her, and they may perform Yibum with her! Since Shimon's act of Chalitzah removed the Isur Kares from him (and replaced it with an Isur Lav), the Isur Kares should also be removed from the other brothers and they thus should have an obligation of Yibum! What is the difference between a case in which Shimon performed Yibum and then died and a case in which he performed Chalitzah, married her, and then died? Why are the other brothers forbidden to her with an Isur Kares while the new brother, Levi, who was born after the Chalitzah, does inherit Shimon's Heter to the woman and is permitted to her?
Similarly, why -- in a case of "Eshes Achiv she'Lo Hayah b'Olamo" (when Levi was born after Reuven died but before Shimon did Yibum) -- is Levi prohibited from doing Yibum with the woman because of the Isur of "Eshes Achiv she'Lo Hayah b'Olamo"? He should inherit Shimon's Heter to the Yevamah when Shimon dies and his wife falls to Yibum!
It must be that when Shimon did Chalitzah, the other brothers were forbidden to her with an Isur Kares for one moment before Shimon married her (because during the time after he did Chalitzah and before he married her, there was no potential for Yibum). As long as there was one moment during which they were forbidden to her and there was no Heter for them to do Yibum, they remain forbidden to her forever. They will never become permitted to do Yibum with her by virtue of Shimon's Heter to her. The same applies to the "Eshes Achiv she'Lo Hayah b'Olamo." Since Levi was forbidden to Shimon's wife before Shimon performed Yibum, he remains forbidden to her under all circumstances.
The same logic dictates that if Levi is born after Shimon does Chalitzah but before Shimon marries her, according to Rebbi Shimon Levi will be forbidden to her for one moment ("Sha'ah Achas") as though he was born before the Yibum during the Zikah. Since there is no potential for Levi to perform Yibum after Shimon's Chalitzah, he never will be permitted to the woman. When the Gemara says that a newborn brother is permitted to the woman after his brother's Chalitzah with her, it must refer to when he was born after the brother remarried the woman. (M. Kornfeld, based on KOVETZ HE'OROS 2:2)
The reason why Levi is permitted to the woman if he is born after Shimon marries her is that from the moment Shimon marries her, the potential for Yibum exists (if he dies without children), and therefore if Levi is born after their marriage it cannot be said that he was forbidden to Shimon's wife for one moment during which there was no potential for Yibum. Before Shimon marries her there is no potential Yibum and thus the newborn brother certainly is forbidden to her because of "Eshes Achiv she'Lo Hayah b'Olamo," and he remains forbidden to her forever. (ME'IRI)

11b----------------------------------------11b

2) CHALITZAH AND YIBUM IN A CASE OF "MACHZIR GERUSHASO"
QUESTIONS: The Gemara discusses whether a woman or her Tzarah is permitted to perform Yibum or Chalitzah in a case of Machzir Gerushaso. The Gemara attempts to bring proof from the Mishnah later (44a) which states that if a man who was married to two women -- one "Pesulah" and one "Kesherah" -- dies, only the Kesherah may do Yibum, and the Pesulah must do Chalitzah. The Gemara asserts that when the Mishnah mentions a woman who is "Pesulah," it refers to a divorced woman (Gerushah) in a case of Machzir Gerushaso. The Gerushah (divorcee) is "Pesulah" because her husband transgresses a Lo Ta'aseh when he remarries her. The Gerushah is not prohibited to anyone else, and thus when her husband dies she falls to Yibum to his brother. The Mishnah teaches that the brother should not do Yibum, but do Chalitzah instead. The deceased brother's second wife (the Tzarah of the Gerushah) is "Kesherah," and the brother may do Yibum with her.
RASHI explains that the Tzarah may do Yibum even though the Torah uses the term "Tum'ah" with regard to Machzir Gerushaso, which implies that the Gerushah has the status of an Ervah. Nevertheless, the word "Tum'ah" refers only to the woman herself (the Gerushah) and not to her Tzarah.
Rashi explains that the Gemara addresses the doubt according to the Lishna Basra, the second version of the question about the Tzarah of the Gerushah. According to the Lishna Basra, the Gemara is in doubt according to the opinion of Rebbi Yosi ben Kifar. Rashi refers to the verse's usage of the term "Tum'ah" because it is Rebbi Yosi ben Kifar who applies that term to Machzir Gerushaso.
Rashi's explanation is problematic. The Mishnah quoted by the Gemara says that the Pesulah -- that is, the Gerushah in the case of Machzir Gerushaso -- may perform only Chalitzah. However, if that Mishnah expresses the view of Rebbi Yosi ben Kifar, the Gerushah herself should not need Chalitzah in the first place because the Torah uses the term "Tum'ah" with regard to Machzir Gerushaso. She is exempt from both Yibum and Chalitzah, like a Sotah and like a woman who is an Ervah. Why does Rashi explain that the Gemara's answer addresses the Lishna Basra and explains the opinion of Rebbi Yosi ben Kifar?
Moreover, the Lishna Basra assumes that the Rabanan maintain that the Gerushah may perform only Chalitzah and that the Tzarah may perform either Chalitzah or Yibum. Accordingly, when the Mishnah says that the "Pesulah" (the Gerushah) may perform only Chalitzah and the "Kesherah" (the Tzarah) may perform either Chalitzah or Yibum, perhaps it is expressing the view of the Rabanan. How can the Gemara prove from that Mishnah what Rebbi Yosi ben Kifar maintains if that Mishnah may be the opinion of the Rabanan? Rashi should explain instead that the Gemara is addressing the doubt of the Lishna Kama, the first version of the question about the Tzarah of the Gerushah. According to the Lishna Kama, Rebbi Yosi ben Kifar maintains that both the Gerushah herself and her Tzarah are exempt from Chalitzah and Yibum, and thus the Mishnah (44a) cannot follow his opinion. The Rabanan, however, maintain that the Gerushah does perform Chalitzah, and the question is whether the Tzarah may perform only Chalitzah or whether she may perform Yibum as well. The Mishnah answers the question and teaches that the Rabanan maintain that the Tzarah may also perform Yibum. (According to the Lishna Kama, the Mishnah cannot be expressing the view of Rebbi Yosi ben Kifar, because he maintains that both the Gerushah and her Tzarah are exempt, while the Mishnah says that they are both required to perform at least Chalitzah). Why does Rashi not explain the Gemara this way? (This is the way TOSFOS (DH Tzarasah, DH Amar Lei) explains the Gemara.)
ANSWER: Rashi understands the Gemara in the same way as the RAMBAN and other Rishonim (11a). They explain that when Rebbi Yosi ben Kifar says that the term "Tum'ah" refers to Machzir Gerushaso (and compares Machzir Gerushaso to a case of Ervah), he does not necessarily exempt the Gerushah from both Chalitzah and Yibum. Although the term "Tum'ah" in the verse of Sotah exempts the Sotah from both Chalitzah and Yibum, the term "Tum'ah" in the verse of Machzir Gerushaso exempts her only from Yibum but not from Chalitzah (see Chart, footnote 5). Accordingly, even Rebbi Yosi ben Kifar does not exempt the Gerushah from Chalitzah. That is why the Gemara suggests that the Mishnah (44a) -- which says that the "Pesulah" (the Gerushah) performs Chalitzah -- may express the view of Rebbi Yosi ben Kifar. (MAHARSHA)
This point -- that Rashi maintains that the use of the term "Tum'ah" does not exempt the Machzir Gerushaso from Chalitzah but only from Yibum -- is implicit in the words of Rashi himself (DH Tzaraso Mahu #1). Rashi adds the words, "[What is the status of the Tzarah] to do Yibum." Rashi implies that there is no question about Chalitzah; she definitely performs Chalitzah even though the verse uses the term "Tum'ah."
How does Rashi know that the Mishnah (44a) follows Rebbi Yosi ben Kifar's opinion, if it also may follow the opinion of the Rabanan (who say that the Gerushah may perform Chalitzah but not Yibum)? The RASHBA and the RITVA write that the Mishnah later cannot follow the opinion of the Rabanan because if it did it would not teach any Chidush. The Rabanan have already taught that the Gerushah herself is Pesulah and may perform only Chalitzah, while the Tzarah is Kesherah and may perform either Chalitzah or Yibum. Only if the Mishnah follows the view of Rebbi Yosi ben Kifar does it teach a Chidush. According to Rebbi Yosi ben Kifar (who says that the term "Tum'ah" applies to the Gerushah), it is a Chidush to say that the term "Tum'ah" does not apply to the Tzarah as it applies to the Gerushah. This must be the Chidush of the Mishnah, and thus the Mishnah must be expressing the opinion of Rebbi Yosi ben Kifar.
Rashi does not seem to follow this approach. The Rashba and Ritva understand that the Gemara's proof is viable according to both versions of Rebbi Yehudah's question. Rashi, however, explains that it provides proof only for the Gemara's second version of the question.
Perhaps Rashi understands that according to both versions of the Gemara's question, the Rabanan maintain that the status of the Tzarah and the status of the Gerushah are the same. According to the principle, "Ein Mikra Yotzei mi'Yedei Peshuto," the term "Tum'ah" must refer to Machzir Gerushaso, and thus both the Gerushah and her Tzarah may perform only Chalitzah and not Yibum (because "Tum'ah" applies to the Tzarah just as it applies to the Gerushah herself). Therefore, when the Mishnah differentiates between a Pesulah (i.e. a Gerushah) and Kesherah (i.e. the Tzarah), it cannot be expressing the view of the Rabanan. It must be following the view of Rebbi Yosi ben Kifar, and the Gemara's question according to the second version is resolved. (M. Kornfeld)