Leviticus 18:9

18:9 You must not have sexual intercourse with your sister, whether she is your father’s daughter or your mother’s daughter, whether she is born in the same household or born outside it; you must not have sexual intercourse with either of them.

Leviticus 20:11

20:11 If a man has sexual intercourse with his father’s wife, he has exposed his father’s nakedness. Both of them must be put to death; their blood guilt is on themselves.

Leviticus 20:21

20:21 If a man has sexual intercourse with his brother’s wife, it is indecency. He has exposed his brother’s nakedness; they will be childless.