Leviticus 16:3-6

“In this way shall Aaron come into the Sanctuary: with a young bull for a sin offering and a ram for a burnt offering. He is to put on the holy linen garment, have the linen undergarments on his body, put on the linen sash, and wear the linen turban—they are the holy garments. He shall bathe his body in water, and put them on. “Then he is to take from the congregation of Bnei-Yisrael two he-goats for a sin offering and one ram for a burnt offering. Then Aaron is to offer the bull for the sin offering which is for himself and make atonement for himself and his house.