Leviticus 16:5-8

He shall take from the congregation of the Israelites [at their expense] two male goats as a sin offering and one ram as a burnt offering. Then Aaron shall present the bull as the sin offering for himself, and make atonement for himself and for his house. He shall take the two goats and present them before the LORD at the doorway of the Tent of Meeting. Aaron shall cast lots for the two goats—one lot for the LORD, the other lot for the scapegoat.