Leviticus 15:16 KJV

And on the eighth day he shall take to him two turtledoves, or two young pigeons, and come before the LORD unto the door of the tabernacle of the congregation, and give them unto the priest:

And the priest shall offer them, the one for a sin offering, and the other for a burnt offering; and the priest shall make an atonement for him before the LORD for his issue.

And every garment, and every skin, whereon is the seed of copulation, shall be washed with water, and be unclean until the even.

The woman also with whom man shall lie with seed of copulation, they shall both bathe themselves in water, and be unclean until the even.