Marriage: The Jews: Obliged to Contract with a Brother's Wife Who Died Without

When brothers dwell together and one of them dies without a son, the widow must not marry outside the family. Her husband’s brother is to take her as his wife and fulfill the duty of a brother-in-law for her.

“Teacher,” they said, “Moses declared that if a man dies without having children, his brother is to marry the widow and raise up offspring for him.