and part of it must be released by ḥalitza. That is, if two women were married to a single man, one of these women must enter into levirate marriage and the other must perform ḥalitza.

The Gemara wonders: So let them say it. Why would it be problematic if people thought that? Even were they to act upon this mistaken assumption it would cause no harm, as there is no transgression involved in performing ḥalitza. The Gemara answers: If he were to consummate the levirate marriage with one and then later proceed to perform ḥalitza with the other, then indeed there would be no reason for concern.

Rather, the requirement to perform ḥalitza with both women is a rabbinic decree that was instituted lest he first perform ḥalitza with one of his brother’s wives and subsequently consummate the levirate marriage with the other. Under such circumstances, he would in fact be violating a prohibition. Once he performs ḥalitza with the first woman he is subject to the prohibition indicated by the verse “So shall it be done to the man who does not build his brother’s house” (Deuteronomy 25:9). In this verse the Merciful One states that once he did not build his brother’s house but rather opted to perform ḥalitza with one of his brother’s wives, he may not proceed to build it by consummating the levirate marriage with a different wife.

Rava said: If the brother who performed levirate betrothal in the case described in the mishna subsequently gave a bill of divorce to that wife in order to nullify his levirate betrothal before he died, her rival wife is rendered permitted to the third brother. The third brother is allowed to consummate the levirate marriage with the wife of the second brother because this wife is no longer considered to be the rival wife of a woman with a double levirate relationship. The bill of divorce serves to nullify the act of levirate betrothal completely. However, the woman with whom the brother performed levirate betrothal and then received the bill of divorce is forbidden to the third brother. Why is this? She might be confused with a woman who receives a bill of divorce. In general cases where levirate betrothal was not performed, if a man gives a yevama a bill of divorce, he is no longer allowed to consummate the levirate marriage with her. If it were permitted to consummate the levirate marriage in this case, people might mistakenly do so in other cases of divorce as well.

There are those who say an alternative formulation of Rava’s statement. Rava said: If the second brother gave a bill of divorce to the wife of the first deceased brother in order to nullify his levirate betrothal to her, then even she herself is permitted to enter into levirate marriage with the third brother. What is the reason for this? That which he performed with her, he removed. The levirate betrothal was completely nullified by the bill of divorce, and it is as though he had done nothing at all. Therefore, as far as the third brother is concerned, she remains with her original, single levirate bond, as though her status had never been changed by the second brother.

MISHNA: In the case where two brothers were married to two sisters, and one of the brothers died, the widow at this point would be exempt from levirate marriage as the sister of his wife. And afterward the wife of the second brother died. Although the yevama is no longer the sister of his wife, this woman is nevertheless forbidden to him forever, since she had already been forbidden to him at one time.

GEMARA: The Gemara asks: Isn’t this obvious? Now, just as there, in the earlier mishnayot, where there was a third brother and so the woman was not disassociated from this household completely, as the levirate obligation existed between her and the third brother to whom she was permitted, you said that she may not enter into levirate marriage because she was forbidden at one time, here, in the case of only two brothers, where she is disassociated from this household completely, is it not all the more so clear that it should be prohibited for her to enter into levirate marriage? The Gemara answers: The tanna taught this mishna at first, at which time he saw it fitting to rule that those other cases are permitted, and therefore he permitted them. And then he subsequently saw it fitting to rule that they are forbidden. And since that case was novel, it was beloved to him, he taught it earlier. But despite the fact that this mishna was no longer necessary, the mishna does not move from its place.

§ The Sages taught: If he engaged in sexual intercourse with this woman who was forbidden to him, he is liable to receive punishment for violating the prohibition against marrying a brother’s wife, because she was never rendered permitted by the levirate mitzva, and he is liable to receive punishment for violating the prohibition against marrying a wife’s sister; this is the statement of Rabbi Yosei. Rabbi Shimon says: He is liable to receive punishment only for violating the prohibition proscribing a brother’s wife. Rabbi Shimon holds that one prohibition does not take effect where another prohibition is already in place, and since she was already forbidden as his brother’s wife, the additional prohibition cannot take effect. The Gemara asks: But isn’t it taught in a baraita, Rabbi Shimon says: He is liable only due to the prohibition against marrying a wife’s sister?

The Gemara answers: This is not difficult. Here, in the second baraita, it is referring to a case where the living brother married his wife first and afterward the brother who is now deceased married her sister. In that case, the first prohibition to take effect on the yevama was that of a wife’s sister, and only later, when she was married to his now-deceased brother, did the additional prohibition proscribing a brother’s wife take effect. There, in the first baraita, it is referring to a case where the brother who is now deceased married his wife first, whereby she became forbidden to the brother as a brother’s wife, and afterward the living brother married her sister, rendering her forbidden as his wife’s sister as well.

The Gemara asks: And according to the opinion of Rabbi Shimon, in a case where the deceased brother married one of the sisters first, in which case she was forbidden to his brother as a brother’s wife, and afterward the living brother married her sister, the only prohibition in place is that of a brother’s wife. Therefore, since the prohibition with regard to a wife’s sister never took effect, then after her husband died she should now enter into levirate marriage. As the prohibition proscribing a brother’s wife is canceled in the face of the levirate mitzva, she should indeed enter into levirate marriage.

Rav Ashi said: The prohibition with regard to a wife’s sister remains suspended. If the prohibition proscribing a brother’s wife is terminated, the prohibition proscribing a wife’s sister comes and takes effect. Therefore, it is clear that the prohibition proscribing a wife’s sister is not completely terminated. Accordingly, when a man dies and the prohibition proscribing a brother’s wife is overridden by the levirate mitzva, the prohibition proscribing a wife’s sister takes effect and she is forbidden to him due to that. The moment the first prohibition ceases to exist, the second immediately takes effect.

The baraita indicates that Rabbi Yosei holds that if the brother consummated the levirate marriage with this woman he violated two prohibitions. The Gemara asks: And does Rabbi Yosei hold that a prohibition takes effect where another prohibition already exists? But isn’t it taught in a baraita: One who committed a transgression deserving of two death penalties is sentenced to the harsher of the two deaths? One would be guilty of such a transgression if he engaged in intercourse with a forbidden relative who was also a married woman, as he would incur one death penalty due to her being a forbidden relative and one death penalty due to her being a married woman. Rabbi Yosei says: He is sentenced according to the first relationship that applied to him with regard to this woman.

And it is taught in a baraita: In what case did Rabbi Yosei say that he is sentenced according to the first relationship that applied to him? If this woman was his mother-in-law who was widowed or divorced, and therefore forbidden to him only due to her status as his mother-in-law, and later she married and became forbidden as a married woman and he engaged in sexual relations with her, then he is sentenced for violating the prohibition proscribing his mother-in-law, since this was the first prohibition to apply. Alternatively, if she was a married woman and then he married her daughter so that she then became his mother-in-law, and then had sexual relations with her, he is sentenced for violating the prohibition proscribing a married woman.