Leviticus 18:19

Also thou shalt not approach unto a woman to uncover her nakedness, as long as she is put apart for her uncleanness.

"'You shall not approach a woman to uncover her nakedness, as long as she is impure by her uncleanness.

And thou shalt not approach unto a woman to uncover her nakedness, as long as she is impure by her uncleanness.

`And unto a woman in the separation of her uncleanness thou dost not draw near to uncover her nakedness.

You must not approach a woman to have sexual relations with her during her menstrual period.