Why did Onan die?

Recall the story of Onan.

⁶ And Judah took a wife for Er his firstborn, and her name was Tamar. ⁷ But Er, Judah's firstborn, was wicked in the sight of the Lord, and the Lord put him to death. ⁸ Then Judah said to Onan, “Go in to your brother's wife and perform the duty of a brother-in-law to her, and raise up offspring for your brother.” ⁹ But Onan knew that the offspring would not be his. So whenever he went in to his brother's wife he would waste the semen on the ground, so as not to give offspring to his brother. ¹⁰ And what he did was wicked in the sight of the Lord, and he put him to death also.

The long-standing tradition is that this expresses God's displeasure with non-procreative ejaculation. I tend to think that if God had such a position, it would be more directly stated. Leviticus doesn't exactly shy away from listing several hundred detailed do's and don't's. Yet nothing like this is ever mentioned, there or anywhere else. (Further, if God had a policy of killing men for such behavior, I think we'd have one serious gender imbalance.) I think we can discount the traditional view.

So what is this really about? What is special about this particular attempt at contraception that it warrants death? If not the action itself, then it must be the context and motivation. Luckily, we're expressly told Onan's motivation: he knew the child would legally be treated as being his late brother's.

Think about this. Onan's brother Er was dead. Women can't inherit in this culture (which is a discussion for a different day). Er had no children, so who stands to inherit Er's property? The nearest male relative: Onan himself! So Onan has a choice: impregnate Tamar, and give her a child that will inherit Er's property so she'll have some way to survive; or leave her destitute and keep it all for himself.

Onan chooses personal gain over helping his brother's widow. Onan is brutally selfish.

But he doesn't stop there! Onan doesn't just refuse to help this woman, as his father Judah later does. He still has sex with her! More than once! Knowing full well he intends to leave her with nothing, this man takes sexual advantage of his dead brother's desperate widow, all the while trying to look the hero. In some places today, that would be called rape by deception.

Onan was a horrible, disgusting, selfish man. God is quite consistent in inflicting punishment for abuse and neglect of the poor. If you look at the reasons Israel is punished during the time of the prophets, it's right up there with worshiping other gods.

Onan abused a poor, helpless widow. His brothers' widow, at that. The lesson of this story has nothing to do with contraception. There's no need to make up a new rule out of nowhere to explain this circumstance.