Leviticus 20:17-21

If a man marries his sister,  whether his father’s daughter or his mother’s daughter, and they have sexual relations,  , it is a disgrace.  They are to be cut off publicly from their people. He has had sexual intercourse with his sister; he will bear his iniquity. If a man sleeps with a menstruating woman and has sexual intercourse with her, he has exposed the source of her flow, and she has uncovered the source of her blood.  Both of them are to be cut off from their people. You must not have sexual intercourse with your mother’s sister or your father’s sister,  for it is exposing one’s own blood relative; both people will bear their iniquity. If a man sleeps with his aunt, he has violated the intimacy that belongs to his uncle;  , they will bear their guilt and die childless. If a man marries his brother’s wife, it is impurity.  He has violated the intimacy that belongs to his brother;  , they will be childless.