May a man marry his brother’s widow, or is it forbidden?

Leviticus states the general rule; Deuteronomy states one exception, with its own conditions and purpose. A man was not to marry his brother’s wife, whether his brother was alive, had divorced her, or had died leaving children. But if brothers lived together and one died “and have no child”, the surviving brother was to marry the widow, so that “the firstborn which she beareth shall succeed in the name of his brother which is dead, that his name be not put out of Israel” (Deuteronomy 25:5-6). This duty, later called levirate marriage, was already known in Judah’s family (Genesis 38:8), and it shapes the story of Ruth (Ruth 4:5, 10).

A general rule with a stated exception is not a contradiction. The two laws even serve the same loyalty: Leviticus guards the brother’s marriage, and Deuteronomy keeps his name and inheritance alive when he has no heir. The penalty in Leviticus 20:21, “they shall be childless”, fits the cases it has in view, where the union takes the brother’s place and gives him no heir. Keil and Delitzsch read it the same way: the prohibition applies where the dead brother left children, for if he died childless his brother was required to marry the widow. John the Baptist applied the general rule to Herod, who had taken Herodias from his brother Philip while Philip was alive: “It is not lawful for thee to have her” (Matthew 14:4).

A duty, not a loophole

Others stress that the exception was a duty rather than a mere permission: a brother who refused it was publicly shamed before the elders (Deuteronomy 25:7-10). The God who gave the general rule also made the exception, for the sake of the dead man’s family.