Leviticus 16:4

16:4 He must put on a holy linen tunic, linen leggings are to cover his body, and he is to wrap himself with a linen sash and wrap his head with a linen turban. They are holy garments, so he must bathe his body in water and put them on.

Leviticus 16:24

16:24 Then he must bathe his body in water in a holy place, put on his clothes, and go out and make his burnt offering and the people’s burnt offering. So he is to make atonement on behalf of himself and the people.