Leviticus 18:6
No one shall approach to any that is his near relation, to uncover his nakedness: I am Jehovah.
Leviticus 18:7-19
The nakedness of thy father, and the nakedness of thy mother, shalt thou not uncover: she is thy mother: thou shalt not uncover her nakedness.
Leviticus 20:11-12
And a man that lieth with his father's wife hath uncovered his father's nakedness: both of them shall certainly be put to death; their blood is upon them.
Leviticus 20:17-21
And if a man take his sister, his father's daughter, or his mother's daughter, and see her nakedness, and she see his nakedness, that is a disgrace; and they shall be cut off before the eyes of the children of their people: he hath uncovered his sister's nakedness; he shall bear his iniquity.