implies that the mishna teaches a case in which ḥalitza is performed ab initio. This indicates that this is the first course of action and the only way to resolve the situation. The Gemara asks further: And let him say to him the following: The mishna prohibits levirate marriage ab initio in this case, due to a rabbinic decree lest he proceed and perform the ḥalitza with the first sister first, whereby it would be prohibited to consummate the levirate marriage with the second. Perhaps for this reason the Sages decreed that it is prohibited to consummate the levirate marriage even if ḥalitza was performed with the second sister. The Gemara answers: It teaches: They may not enter into levirate marriage. This indicates that the halakha of levirate marriage does not apply here at all. Accordingly, even after the fact, if he performed ḥalitza with the second sister, the halakha of levirate marriage would not apply to the first sister.

The Gemara asks: And let him say to him a different reason for the ruling of the mishna: It is due to a rabbinic decree lest the second brother die, and it is prohibited to negate the mitzva of levirate marriage. Perhaps for this reason it would be forbidden to consummate the levirate marriage in the case where two sisters happened before him for levirate marriage, and not due to the prohibition proscribing the sister of a woman with whom he has a levirate bond. The Gemara answers: Rabbi Yoḥanan was not concerned over the possibility of the death of a brother, and in his opinion there is no need to make a decree to address such cases.

The Gemara asks: And let Rabbi Yoḥanan say to him that this mishna is in accordance with the opinion of Rabbi Elazar, who said: Once the yevama stood before him at one time as forbidden, even if it was not at the time that she happened before him, she remains forbidden to him forever. Perhaps the mishna could be explained according to Rabbi Elazar’s opinion. The Gemara answers: Since the opinion of Rabbi Elazar is cited explicitly in the latter clause of the mishna, it can be deduced that the first clause is not according to the opinion of Rabbi Elazar. Therefore, this ruling cannot be attributed to Rabbi Elazar.

The Gemara asks: And let him say to him that here the reference is to a situation where the two brothers died at once, and consequently both of the women happened before the yevamin for levirate marriage at the same time. And this mishna is in accordance with the opinion of Rabbi Yosei HaGelili, who says: It is possible to be precise. It is possible to determine that two events occurred at exactly the same moment, both sisters were forbidden at the time that they happened before the brothers-in-law. The Gemara answers: The tanna did not teach an unattributed mishna in accordance with the opinion of Rabbi Yosei HaGelili. Any time the mishna is cited in accordance with Rabbi Yosei HaGelili’s opinion, it is always attributed to him explicitly.

The Gemara asks: And let him say to him a different explanation for the ruling: This mishna is indeed addressing a case where the brothers died one after the other, yet we do not know which sister happened before the yevamin for levirate marriage first. In that case, it would be impossible to determine which sister would be permitted.

The Gemara answers: If so, that which the mishna teaches in the latter clause: And if they married their wives before consulting the court they should divorce them, is difficult. Why must they divorce their wives in this situation? Granted, the brother who took the first sister in levirate marriage must divorce her, as we say to him: Who permitted her to you? Indeed, she was forbidden as the sister of a woman with whom he had a levirate bond, and so he must divorce her. However, the brother who took the second sister could say: My fellow brother consummated the levirate marriage with the second sister, but I am consummating the levirate marriage with the first sister. It is possible that after the other brother consummated the levirate marriage with the second sister, the first sister would then be permitted to him after the fact, and he is not required to divorce her unless it is certain that he violated a prohibition.

The Gemara concludes: Indeed, this is what Rabbi Yoḥanan meant when he said to Rabbi Yosei bar Ḥanina: I do not know who taught: Sisters, for according to these considerations he cannot properly resolve the ruling of this mishna.

We learned in the mishna: If one of the sisters was forbidden to one of the brothers due to a prohibition against forbidden relatives because she was a relative of his wife or a relative from his mother’s side, then he is prohibited from marrying her but permitted to marry her sister. But the second brother, who is not a close relative of either sister, is prohibited from marrying both of them. It enters your mind to say that a forbidden woman, such as his mother-in-law, happened before the yavam for levirate marriage first.

Accordingly, the Gemara asks: And why would both women be forbidden to the second brother? Let the son-in-law rise and consummate the levirate marriage with the sister who is not his mother-in-law first. Consequently, with regard to the other brother, his mother-in-law would be considered a yevama who was permitted to perform levirate marriage at the time that she happened before him, and then forbidden when her sister happened before him for levirate marriage as well, and then subsequently became permitted when his brother consummated the levirate marriage with her sister. If so, the mother-in-law should return to her original permitted status and may enter into levirate marriage with him.

Rav Pappa said: The mishna is referring to a case where the woman who was not his mother-in-law happened before the brothers for levirate marriage first, in which case she was permitted to both of them. When her sister, i.e., the mother-in-law, happened before them for levirate marriage as well, both women were rendered forbidden to the second brother, as each one is the sister of a woman with whom he has a levirate bond. Because the mother-in-law was forbidden from the time that she happened before the yavam for levirate marriage, she can never be permitted to him.

§ With regard to the case of two brothers who married their wives before consulting the court, the mishna states that the women should be divorced. Rabbi Eliezer disagrees and says that this is a matter of dispute between Beit Shammai and Beit Hillel, as Beit Shammai say: They may maintain them as their wives, and Beit Hillel say: They should divorce them. An expanded version of this discussion is taught in the Tosefta (5:1): Rabbi Eliezer says that Beit Shammai say: They may maintain them as their wives, and Beit Hillel say: They should divorce them. Rabbi Shimon says: They may maintain them as their wives. Abba Shaul disagrees with Rabbi Eliezer and says: This was a matter of leniency for Beit Hillel. They were the ones who put forth a lenient ruling, as Beit Shammai say: They should divorce them, and Beit Hillel say: They may maintain them as their wives.

The Gemara asks about this baraita: In accordance with whose opinion is the statement of Rabbi Shimon? This matter is a dispute between Beit Hillel and Beit Shammai, with different versions of their opinions, and therefore Rabbi Shimon should not have formulated the halakha in this manner. Indeed, if he holds in accordance with the opinion of Beit Shammai, then that is the same as the opinion of Rabbi Eliezer. He would thereby conclude that the halakha is in accordance with the opinion of Beit Shammai, as per Rabbi Eliezer’s version. If so, he should have formulated his opinion in that way. If, however, he holds in accordance with the opinion of Beit Hillel, then that is the opinion of Abba Shaul. The Gemara responds: This is what he is saying: Rabbi Shimon actually maintains a third opinion: Beit Shammai and Beit Hillel did not dispute this matter; both agreed that the marriages may be maintained.

§ The mishna stated: If one of the sisters was forbidden to one of the brothers due to a prohibition against forbidden relations, then he is prohibited from marrying her but permitted to marry her sister. The Gemara asks: We already learned this on one occasion: When her sister, who is a forbidden relative to the yavam, is her yevama as well, she either performs ḥalitza or enters into levirate marriage.

The Gemara answers: It is necessary that this be said here as well, for if it taught us this halakha only there in its more general formulation (Yevamot 20a), then I might have said: The yavam is permitted to marry the sister because there is no reason to issue a rabbinic decree due to a second brother. There, there is only one yavam, to whom one sister is permitted and the other is forbidden. Here, however, in the case of two brothers, where there is reason to issue a rabbinic decree due to the second brother, lest he consummate the levirate marriage as well, I would say that we do not allow even the first brother to perform levirate marriage, and both sisters-in-law should be forbidden to both brothers.

And if the mishna had taught us the halakha only here, it would have been possible to say that the permissibility of levirate marriage here is because there is a second brother who indicates, by refraining from performing levirate marriage, that the sister of a woman bound by a levirate bond is forbidden. However, there, where there is not a second brother, I would say no, this halakha would not apply, due to a concern that people might wrongly conclude that the sister of a woman bound by a levirate bond is permitted. Therefore, it is necessary to state this halakha in both places.

It was taught in the mishna: If one of the sisters was forbidden to one of the brothers due to a prohibition resulting from a mitzva or due to a prohibition stemming from sanctity, then her sister must perform ḥalitza and may not enter into levirate marriage. The Gemara wonders: We already learned this as well: