In ancient Jewish culture,  when a man died without a son, his property went to his closest male relative, often a brother, potentially leaving his widow impover­ished. Thus, the Levirate law (from the Latin for “brother”) stated that the next oldest brother was required to marry the widow so she could bear a son in the name of her deceased husband. This child would be legally considered his dead brother’s progeny and therefore receive his inheritance. Subsequent children from the marriage would belong to the living brother. The Levirate law preserved a dead man’s inheritance, so “his name won’t be wiped out from Israel” and that property would follow the appropriate lines of inheritance. It also protected and provided for widows without male children, so they could retain the land of their deceased husband through their son. It was considered a major offense to neglect this duty to one’s dead brother.

When brothers live together and one dies without a son, the wife of the deceased won’t go outside to a man who’s a stranger. Her husband’s brother will go, take her as his wife, and do his duty. Then the firstborn she bears will be raised in the name of his dead brother, so his name won’t be wiped out from Israel. But if the man doesn’t want to take his brother’s wife, then his brother’s wife will go to the gate and tell the elders, “My husband’s brother refuses to raise up a name for his brother in Israel. He won’t do his duty.”

Then the city elders will call him and speak with him. If he’s adamant and says, “I don’t want to take her,” then his brother’s wife will come into the elders’ sight and remove the shoe from his foot and spit in his face. Then she’ll say, “This is how it’s done to the man who doesn’t build his brother’s house.”

Then his name in Israel will be called, “The House of the Removed Shoe.”

– Deuteronomy 25:5-10

The Levirate law is described firsthand in the story of Judah and his widowed daughter-in-law Tamar. The Bible records that Judah’s firstborn son Er died, leaving his widow Tamar childless. According to the law, Judah then instructed his next son Onan to marry her to raise up a son for his dead brother. However, Onan, knowing the child wouldn’t be his, “spilled [his semen] on the ground so as to not give seed to his brother” (Genesis 38:9). In refusing to produce an heir for Er, Onan was essentially attempting to steal the double portion of inheritance due to the firstborn. God was not pleased with Onan and put him to death for his treachery.

With his two oldest sons dead, Judah was supposed to give his twice-widowed daughter-in-law to his third son, Shelah, but was afraid that he too would die. Therefore, Judah sent Tamar back to her own family, telling her to wait until Shelah grew up, with no intention of actually having them marry. Bereft and disgraced, Tamar eventually took matters into her own hands. Disguising herself as a prostitute, she enticed and slept with her father-in-law and conceived. When her pregnancy became apparent, Judah was informed, who was still Tamar’s legal guardian despite banishing her from his household. Judah ordered her to be executed. However, when she presented proof that she was pregnant with Judah’s child, Tamar was exonerated. Judah’s words: “She is more righteous than I, since I didn’t give her to my son Shelah” (Genesis 38:26).

In the end, Tamar proved herself to be a shrewd (albeit audacious) woman. Although she tricked her father-in-law into illicit intercourse, which would normally be punishable by death, she was actually obtaining something that was rightfully hers – a legal heir from her first marriage. It was Judah who was guilty of the greater offense by failing to uphold the Levirate law.