Contradiction with Deuteronomy 25:5
This verse allows a brother to marry his deceased brother's wife, which contrasts with the restrictions on sexual relations with in-laws in Leviticus 18:15.
Deuteronomy 25:5: If brethren dwell together, and one of them die, and have no child, the wife of the dead shall not marry without unto a stranger: her husband's brother shall go in unto her, and take her to him to wife, and perform the duty of an husband's brother unto her. [her husband's...: or, her next kinsman]