Leviticus 20:17-21

‘If there is a man who takes his sister, his father’s daughter or his mother’s daughter, so that he sees her nakedness and she sees his nakedness, it is a disgrace; and they shall be cut off in the sight of the sons of their people. He has uncovered his sister’s nakedness; he bears his guilt.

If there is a man who sleeps with a menstruous woman and uncovers her nakedness, he has exposed her flow, and she has uncovered the flow of her blood; so both of them shall be cut off from among their people.

You shall also not uncover the nakedness of your mother’s sister or of your father’s sister, for such a one has uncovered his blood relative; they will bear their guilt.

If there is a man who sleeps with his uncle’s wife, he has uncovered his uncle’s nakedness; they will bear their sin. They will die childless.

If there is a man who takes his brother’s wife, it is detestable; he has uncovered his brother’s nakedness. They will be childless.