Leviticus 16:10-11

10The other goat, the scapegoat chosen by lot to be sent away, will be kept alive, standing before the Lord. When it is sent away to Azazel in the wilderness, the people will be purified and made right with the Lord.

11“Aaron will present his own bull as a sin offering to purify himself and his family, making them right with the Lord. After he has slaughtered the bull as a sin offering,