Leviticus 16:6-11, 21-22, 29-30, 34

“Aaron shall offer the bull as a sin offering for himself and shall make atonement for himself and for his house. Then he shall take the two goats and set them before the LORD at the entrance of the tent of meeting. And Aaron shall cast lots over the two goats, one lot for the LORD and the other lot for Azazel. And Aaron shall present the goat on which the lot fell for the LORD and use it as a sin offering, but the goat on which the lot fell for Azazel shall be presented alive before the LORD to make atonement over it, that it may be sent away into the wilderness to Azazel. “Aaron shall present the bull as a sin offering for himself, and shall make atonement for himself and for his house. He shall kill the bull as a sin offering for himself.

And Aaron shall lay both his hands on the head of the live goat, and confess over it all the iniquities of the people of Israel, and all their transgressions, all their sins. And he shall put them on the head of the goat and send it away into the wilderness by the hand of a man who is in readiness. The goat shall bear all their iniquities on itself to a remote area, and he shall let the goat go free in the wilderness.

“And it shall be a statute to you forever that in the seventh month, on the tenth day of the month, you shall afflict yourselves and shall do no work, either the native or the stranger who sojourns among you. For on this day shall atonement be made for you to cleanse you. You shall be clean before the LORD from all your sins.

And this shall be a statute forever for you, that atonement may be made for the people of Israel once in the year because of all their sins.” And Aaron did as the LORD commanded Moses.