Leviticus 20:10-12

10“If a man commits adultery with another man’s wife or with his neighbor’s wife, both he and the woman must be put to death for their adultery.

11Whoever has sexual intercourse with his father’s wife has violated his father’s marriage. Both he and his father’s wife must be put to death. They deserve to die.

12If a man has sexual intercourse with his daughter-in-law, both of them must be put to death. They have done a disgusting thing and deserve to die.