Leviticus 18:9; Leviticus 20:17

xYou shall not uncover the nakedness of your sister, your father's daughter or your mother's daughter, whether brought up in the family or in another home.


17 iIf a man takes his sister, a daughter of his father or a daughter of his mother, and sees her nakedness, and she sees his nakedness, it is a disgrace, and they shall be cut off in the sight of the children of their people. He has uncovered his sister's nakedness, and he shall bear his iniquity.