Leviticus 20:17-21

17If a man takes his sister, his father’s daughter, or his mother’s daughter, and sees her nakedness, and she his, it is a shameful thing. They are to be cut off in the sight of the children of their people, for he has uncovered his sister’s nakedness, and will bear his iniquity.

18If a man lies with a woman during her niddah and exposes her nakedness, he has exposed her flow and she has uncovered the flow of her blood. Both of them are to be cut off from among their people.

19You are not to uncover the nakedness of your mother’s sister, or your father’s sister, for the one who does that has made his close relative naked, and will bear his iniquity.

20If a man lies with his aunt, he has uncovered his uncle’s nakedness. They should bear their sin, and die childless.

21If a man takes his brother’s wife, it is an impurity. He has uncovered his brother’s nakedness, and they will be childless.