Leviticus 18:6
No man shall approach any woman that is near of kin to him, to uncover her nakedness. I am the LORD.
Leviticus 18:7-19
The nakedness of thy father or the nakedness of thy mother, thou shalt not uncover; she is thy mother; thou shalt not uncover her nakedness.
Leviticus 20:11-12
And the man that lies with his father's wife has uncovered his father's nakedness; both of them shall surely die; their blood shall be upon them.
Leviticus 20:17-21
And if a man shall take his sister, his father's daughter, or his mother's daughter and see her nakedness, and she see his nakedness; it is a wicked thing; and they shall be killed in the sight of the sons of their people; he has uncovered his sister's nakedness; he shall bear his iniquity.