'Uncover Her Nakedness' in the Bible

You shall not uncover the nakedness of your father’s wife’s daughter; born to your father, she is your sister.

If a man lies [intimately] with a woman during her menstrual cycle and uncovers her nakedness, he has exposed her flow, and she has uncovered the flow of her blood; both of them shall be cut off from their people [excluding them from the atonement made for them].