“Judah said to Onan: Consort with your brother’s wife, and consummate levirate marriage with her, and establish offspring for your brother” (Genesis 38:8). “Judah said to Onan…” – Judah was the first to initiate the mitzva of levirate marriage. It is taught: Any matter that was in the category of permitted, became prohibited, and then became permitted again, it does not return to its initial permitted state, but rather, to a second permitted state.
A yevama,29A yevama is a woman whose husband died without children. She is tied in a levirate bond to his brother, who is called the yavam. because she was in the category of permitted, became prohibited, and was then permitted,30Before she married, she was permitted to marry the brother of her eventual husband. Once she married, she became forbidden to her husband’s brother. When her husband died, she became permitted to him once again. does she, perhaps, return to her initial permitted state?
The verse states: “Her husband’s brother shall consort with her” (Deuteronomy 25:5) – mitzva.31This view accords with that of Abba Shaul (Yevamot 39b), who holds that levirate marriage may be performed only if the intent in doing so is to perform the mitzva, and not if the intent is simply because they would like to be married. This is different from the permitted status of the yevama to her eventual yavam before she had been married.
At that time they could have married for any reason they wanted (Yefe To’ar). Rabbi Yosei bar Ḥalafta entered into levirate marriage with his brother’s wife. He engaged in relations five times,32He had five brothers who died without children. He did not remain married to these women, but after he fulfilled the mitzva he divorced them. he engaged in relations through a sheet,33This was in order to minimize his pleasure, so he would ensure that the act was purely for the sake of the mitzva. and planted five saplings in Israel.34Five sons were born from these acts of levirate marriage.
Who were they? Rabbi Yishmael ben Rabbi Yosei, Rabbi Elazar ben Rabbi Yosei, Rabbi Menaḥem ben Rabbi Yosei, Rabbi Ḥalafta ben Rabbi Yosei, and Rabbi Avdimos ben Rabbi Yosei. He had red eyes and resembled his mother.35Rabbi Avdimos had red eyes, as did his mother. This was considered unattractive, and underscores that Rabbi Yosei was interested only in fulfilling the mitzva of levirate marriage, and therefore he did so even in this case, where the woman was not attractive.
“Onan knew that the offspring would not be his, and it was when he consorted with his brother’s wife, that he spilled on the ground, so as not to give offspring for his brother” (Genesis 38:9). “Onan knew” – he would penetrate inside but spill outside. “Judah said to Tamar, his daughter-in-law: Remain a widow in your father’s house, until Shela my son matures; for he said: Lest he too die, like his brothers.
Tamar went and lived in her father’s house” (Genesis 38:11). “Judah said to Tamar, his daughter-in-law” – Rabbi Elazar said: Although there is no divination, there is a portent – “lest he too die, like his brothers.” The Rabbis say: [With regard to a] house, baby, and wife,36When a person builds a house, has a child, or marries, and then experiences a period of good or bad fortune, the experience can be seen as a portent for that fortune continuing.
Viewing it in this way would not violate the prohibition against divination. although there is no divination, there is a portent.