It is the Jewish woman who is privileged with bestowing Jewishness to her offspring. Yet while the mother determines the Jewish status--or lack thereof--of her offspring, it is the father who determines particular family status. Thus, whether one is Kohen, Levi, or Yisrael is determined by the father.
This distinction between the relationship created by the mother and that created by the father is brought into focus as we study the opening Mishnah of the second chapter of Yevamot. The opening Mishnah of the first chapter listed the fifteen relatives with whom one may not perform yibum. The first fourteen of these are blood relatives of the brother or of the wife, disqualifying them--and their co-wives--from yibum and thus, the need for chalitzah. The discussion regarding the fifteenth relative, "the wife of one's brother who was not in his world", is the subject of the opening Mishnah of the second chapter of Yevamot. While the other fourteen cases are clear enough, the fifteenth case is not.
"How [do we understand] 'the wife of the brother who was not in the world?'" the Mishnah asks (Yevamot 17a). The Mishnah explains that such a case involves "two brothers, and one of them dies; and a [third] brother is then born". The second brother then does yibum with his deceased brother's widow, and then he himself dies. As the third brother was never alive simultaneously with his older brother (the first one)--"they were not in the world" together--there is no obligation to do either yibum or chalitzah with the widow of this brother. Furthermore, there is also no obligation of yibum or chalitzah with the other widows of the second brother, either--the one who was alive at the same time as the third brother--as all fifteen women exempt all their co-wives.
This exemption is exegetically derived by Rav, the third century Babylonian Sage, from biblical terminology used in describing the mitzvah of yibum where the Torah states, "when brothers dwell yachdav, together, and one of them dies" (Devarim 25:5). The Sages understood the word "together" to mean that the brothers had to be alive together, i.e. at the same time, for the obligation of yibum to be operative. The Gemara further derives from the word yachdav that the obligation of yibum only applies when the brothers are "designated [together] in inheritance". As inheritance passes from the father to his sons, only paternal brothers share in the inheritance[1] and thus only paternal brothers are obligated in yibum. Rava, however, derives the law that yibum only applies to paternal brothers from a different source--from the first encounter between Yosef and his unknowing brothers. Accused of being spies, they responded, "Twelve brother are we, the sons of one man" (Breisheet 42:13).
If we are basing these teachings on the use of the term "brother," why not, asks the Gemara, derive the definition of brotherhood from that of prohibited sexual unions? "The nakedness of your brother's wife you shall not uncover" (Vayikra 18:16). As "your brother" in this case included a half brother on one's mother's side, why not apply yibum to both maternal and paternal brothers? The Gemara gives a technical answer basing such on the specific wording of the verse. It then asks, why not derive the laws of yibum from the verse (which we will read this Shabbat), "And Abram said to Lot: 'Let there be no strife between us...for we are brothers'" (Breisheet 13:8). As Abraham and Lot were actually uncle and nephew, why not derive that yibum also applies to one's aunt? The Gemara offers another technical response.
Biblical exegesis and technical legal arguments reflect important ideas and ideals. "When two brothers sit together, and one of them dies". Underpinning the mitzvah of yibum is respect and love for one's brother and concern for his legacy. How odd it sounds to us moderns that one would marry one's brother's widow! Yet that is what the Torah expects, and what concern for one's family means.
Such an idea cannot be derived from Lot, who epitomizes the breaking up of families. He owed so much to his uncle, including his very life, yet Lot left him to go get a high-paying job in the thriving and decadent city of Sedom. Deriving the laws of yibum from the laws of sexual immorality might imply that there is something unseemly in marrying one's sister-in-law, a notion from which the Torah wants to disabuse us.
Rather, it is the story of Yosef that serves as our model. Yes, there was much brotherly hatred, and awful things were done. But ultimately, the brothers reunited and formed the Jewish nation--not much different, if perhaps more extreme, than many of our relationships. Even the context of the verse used is telling, describing the accusation that the brothers were spies. It was through the brother's reaction to this accusation that they demonstrated their concern for their brother Binyamin, thereby demonstrating that they had repented from their treatment of Yosef.
How we learn something is often as important, if not more so, than what we learn.
[1] When a woman passes away, her husband generally inherits her estate. This is not the place for a discussion of the philosophy and laws of inheritance. For now, it will suffice to note that, in theory, all money in the family is under the domain of the man, who then has responsibility for the family. Please G-d, we will discuss this further when we get to the eighth chapter of Bava Batra in May, 2017.
