Ellen Flax (I believe she’s a rabbi) gave an interesting d’var Torah (word of Torah/Bible) on
the story of Yehudah/Judah, Onan, and Tamar (found in Parshat Vayeshev, Genesis 37:1 - 40:23), at
Ansche Chesed’s
Minyan Rimonim last Shabbat (Sabbath) morning. She posited that Onan was killed by HaShem not because he “spilled seed,” refusing to impregnate Tamar because her first child would have considered his deceased brother’s/her late husband’s child, but because he used Tamar for sex. Well, yes and no.
I suppose that we should first discuss the institution of yibum/levirate marriage. Here's a (the principle?) biblical quote discussing the matter:
Parshat Ki Tetze, Deuteronomy, chapter 25, verses 5-6:
5 If brethren dwell together, and one of them die, and have no child, the wife of the dead shall not be married abroad unto one not of his kin; her husband's brother shall go in unto her, and take her to him to wife, and perform the duty of a husband's brother unto her.
6 And it shall be, that the first-born that she beareth shall succeed in the name of his brother that is dead, that his name be not blotted out of Israel.
My understanding is that the institution of yibum/levirate marriage cut both ways. On the one hand, it was a way of attempting to ensure that a deceased man would have a child who was considered his descendent. On the other hand, it was also a form of economic protection for women, who didn’t have many respectable options for making an independent living. My impression is that a woman of the biblical era was dependent on the men of either the family of her birth or of her husband’s family for her financial support, and that, therefore, attempting to ensure that she had at least one child would guarantee her support by her late husband’s male relatives. A childless widow seems to have been returned to her father’s family for financial support, a development that may not have been welcomed, since her father may have thought that he’d already ensured his daughter’s economic survival by marrying her off. (I’m probably not the only one who knows older parents who’ve found themselves with adult children living at home again after a marriage that did not work out and/or for financial, health, or other reasons.)
It’s true that Onan was clearly using Tamar for sex, since he refused to try to get her pregnant. But, despite Ellen’s protestations that Onan’s death was not about children, I don’t think that one can divorce sex from children in this context. I can’t help thinking that Onan’s grandfather, Yaakov Avinu (Jacob Our Father), had two full-fledged wives and two, er, concubines (if I may be so politically incorrect as to use that term). In those days, before rabbis even existed, much less had forbidden polygamy, what was to prevent Onan from marrying other women, having children with them, and leaving Tamar chained to him in marriage and with no opportunity ever to have a child for the rest of her life, just to spite his deceased older brother? Alternatively, he could have "accused" Tamar of infertility and divorced her, which could have reduced both her financial circumstances and her possibilities for remarriage. Either course of action would have been abusive, and it could be argued, from a traditional perspective, that HaShem took Onan's life to prevent him from pursuing either one.
Afterthought: Perhaps it's no coincidence that, though levirate marriage was obviously an accepted practice even before it was presented as a law to the Jewish people, the loophole around that requirement doesn't appear until Deuteronomy (see Ki Tzetze link above, verses 7-10), several books after the one that contains the story of the gutsy Tamar (see first link in this post).
The story of Tamar gives new meaning to the old slang saying, "Take no prisoners." On the one hand, by discreetly accusing Yehudah of failing to fulfill his obligations while avoiding mentioning him by name, she did not take Yehudah prisoner. On the other hand, she showed the extraordinary lengths to which a woman is willing to go to avoid being imprisoned herself, and serves as a cautionary tale to those men who think that they can get away with being heartless.