Leviticus 20:17-19

Complete Jewish Bible

¹⁷ If a man takes his sister, his father’s daughter or his mother’s daughter, and has sexual relations with her, and she consents, it is a shameful thing; they are to be cut off publicly — he has had sexual relations with his sister, and he will bear the consequences of their wrongdoing. ¹⁸ If a man goes to bed with a woman in her menstrual period and has sexual relations with her, he has exposed the source of her blood, and she has exposed the source of her blood; both of them are to be cut off from their people. ¹⁹ You are not to have sexual relations with your mother’s sister or your father’s sister; a person who does this has had sexual relations with his close relative; they will bear the consequences of their wrongdoing.