Daf Yomi - Yevamos 7 - Highlights

Rav Simi bar Ashi said: The Tanna who used the verse to teach us that Beis Din may not perform an execution on Shabbos did not need the verse because otherwise we would have thought that a positive commandment overrides a prohibition even though it involves kares. Rather, the verse was necessary, for otherwise we would have derived that Beis Din can execute a capital offender on Shabbos through the means of the following kal vachomer: Avodah (service in the Beis Hamikdosh) overrides Shabbos (the kohanim may perform the service on Shabbos), nevertheless, execution overrides avodah (a kohen, who has committed murder and was sentenced to death, Beis Din sends agents to bring him to be executed even if he wishes to perform the avodah); Shabbos, which is overridden by the avodah, shouldn’t an execution certainly override it (Beis Din should be permitted to perform an execution on Shabbos). This is why the verse “in any of your dwellings” was necessary; teaching us the halacha that Beis Din may not perform the execution. (6b – 7a)

The Gemora concludes that there is no source to teach us that the positive commandment of yibum will override the kares prohibition of taking his wife’s sister; nevertheless the verse aleha is required to teach us that he may not.

The Gemora explains: (One of the thirteen principles of Biblical exegesis is as follows: Something that was included in the general rule, and departed from that rule to teach something new, did not depart to teach only about itself, but rather to teach about the entire general rule.)

The Gemora cites an example where this principle is applied. It is written [Vayikra 17:20]: A person who eats flesh from the shelamim offering while his tumah is upon him, that soul shall be cut off from its people. Shelamim did not have to be mentioned separately, since they are included in the general rule of sacred offerings; why then are they mentioned separately? It is to teach us that only sacrifices brought to the altar are included in this rule, however animals dedicated to the Temple upkeep are excluded, and they are not subject to the kares penalty if eaten in a state of tumah.

The Gemora now explains how this principle is relevant to yibum. The prohibition of taking a brother’s wife was included in the general prohibition of all arayos (forbidden relations), and it was singled out in regards to yibum. This teaches us that just as this prohibition is permitted for the sake of yibum, so too all other arayos will be permitted for the sake of yibum.

The Gemora objects to this comparison between the two cases: By the halachos of tumah, both the general rule (all sacrifices) and the one singled out (shelamim) are dealing with prohibitions; whereas here by yibum, the general rule (all arayos) is dealing with the prohibition and the one which is singled out (brother’s wife) is permitted. (7a)

The Gemora states that this (the permissibility of yibum to a brother’s wife) is compared to a different principle. (One of the thirteen principles of Biblical exegesis is as follows: Something that was included in the general rule, and departed to be treated as a new case; you cannot return it to its general rule unless the Torah returns it explicitly.)

The Gemora cites an example where this principle is applied. It is written regarding a metzora [Vayikra 14:13]: He shall slaughter the (asham) lamb in the place where one slaughters the chatas and the olah, in a holy place. For the asham is like the chatas, for the kohen. What is this verse coming to teach us? Was it not already stated regarding the law of the asham that it was required to be slaughtered in the north? The Gemora answers: Since this asham departed from other asham’s insofar as it requires the placing of its blood on the right thumb and big toe of the metzora, one might think that it should not require blood applications or the burning of its sacrificial parts on the altar. The Torah, therefore, says: For the asham is like the chatas, teaching us that just like a chatas requires blood applications and the burning of its sacrificial parts on the altar, so too, the metzora’s asham requires blood applications and the burning of its sacrificial parts on the altar.

The Gemora concludes: Here also, by yibum, all arayos were prohibited and a brother’s wife was excluded from the general rule and became permitted for the sake of yibum; only a brother’s wife should be permitted, but all other prohibitions should remain prohibited even in a case of yibum. Accordingly, why did the Torah require a verse prohibiting yibum with one’s wife’s sister? (7a – 7b)

The Gemora offers another reason why the verse aleha is required to teach us that he may not perform a yibum on his wife’s sister. Perhaps we would have made a comparison to a brother’s wife. Just like one can perform a yibum on his brother’s wife (even though, she should be forbidden, if not for the mitzvah of yibum), so too, one can perform a yibum on his wife’s sister.

The Gemora asks: How can the two cases be compared? By a regular case of yibum, there is only one prohibition, whereas here, there are two prohibitions?

The Gemora answers: We might have thought that once the prohibition of taking a brother’s wife has been lifted, so too, the prohibition of taking his wife’s sister should also be lifted. (7b)

The Gemora asks: How do you know that this (when one prohibition is lifted, so too, another one should also be lifted) is a valid principle?

The Gemora answers: It was taught in a braisa: A metzora whose eighth day (of purification) fell on Erev Pesach, but on that day had an emission of semen (resulting in the fact that he now cannot enter the Temple Mount to complete his purification process), and then immersed himself, the Chachamim said that although an ordinary tevul yom (one who has immersed in a mikvah but still has tumah on him until nightfall) may not enter the Temple Mount until nightfall, this one may enter in order to complete his purification process, thus enabling him to bring his pesach offering. It is preferable for a positive commandment that involves kares (pesach obligation) to override a positive commandment that does not involve kares (entering the Temple Mount while being a tevul yom).

Rabbi Yochanan maintains that it is only Rabbinically forbidden for a tevul yom to enter the Temple Mount.

Ula said: Why do we allow this tevul yom to enter? He answers: Since we would allow an ordinary metzora to enter the Temple Mount in order to complete his purification process, we allow a metzora who has had an emission of semen to enter as well.

This is used as support for our logic regarding yibum. We might have thought that once the prohibition of taking a brother’s wife has been lifted, so too, the prohibition of taking his wife’s sister should also be lifted. This is why the verse aleha is needed to teach us that one cannot perform a yibum with his wife’s sister. (7b)