Leviticus 16:23-25

23“Then Aaron shall come into the Tent of Meeting and take off the linen garments which he put on when he went into the Holy Place (Holy of Holies), and shall leave them there.

24He shall bathe his body with water in a holy place and put on his clothes, and come out and offer his burnt offering and that of the people, and make atonement for himself and for the people.

25And he shall offer up in smoke the fat of the sin offering on the altar.