Leviticus 18:6-9

⁶No man shall come nigh to any of his own flesh to uncover the nakedness; I am the Lord.

⁷The nakedness of thy father, or the nakedness of thy mother, thou shalt not uncover. She is thy mother; thou shalt not uncover her nakedness.

⁸The nakedness of thy father’s wife thou shalt not uncover, it is thy father’s nakedness.

⁹The nakedness of thy sister, the daughter of thy father, or the daughter of thy mother, who hath been begotten of thy father by another wife, or of thy mother by another husband, their nakedness thou shalt not uncover.