Leviticus 20:17

20:17 “‘If a man has sexual intercourse with his sister, whether the daughter of his father or his mother, so that he sees her nakedness and she sees his nakedness, it is a disgrace. They must be cut off in the sight of the children of their people. He has exposed his sister’s nakedness; he will bear his punishment for iniquity.

Leviticus 20:19

20:19 You must not expose the nakedness of your mother’s sister and your father’s sister, for such a person has laid bare his own close relative. They must bear their punishment for iniquity.