Leviticus 16:10-11

But the goat, on which the lot fell for Azazel, shall be set alive before Jehovah, to make atonement for him, to send him away for Azazel into the wilderness. And Aaron shall present the bullock of the sin-offering, which is for himself, and shall make atonement for himself, and for his house, and shall kill the bullock of the sin-offering which is for himself.