Leviticus 16:7-10

Then he must take the two male goats and present them to the LORD at the entrance of the Tabernacle. He is to cast sacred lots to determine which goat will be reserved as an offering to the LORD and which will carry the sins of the people to the wilderness of Azazel. Aaron will then present as a sin offering the goat chosen by lot for the LORD. The 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.