Leviticus 16:23-24

23And Aaron shall go into the tent of meeting, and shall put off the linen garments, which he put on when he went into the sanctuary, and shall leave them there;

24and he shall bathe his flesh with water in a holy place, and put on his garments, and go forth, and offer his burnt-offering, and the burnt-offering of the people, and make atonement for himself, and for the people.