Leviticus 16:1-2, 15-17

After the death of Aaron’s two sons—they died when they came before GOD with strange fire—GOD spoke to Moses: “Tell your brother Aaron not to enter into the Holy of Holies, barging inside the curtain that’s before the Atonement-Cover on the Chest whenever he feels like it, lest he die, because I am present in the Cloud over the Atonement-Cover.

“Next he will slaughter the goat designated as the Absolution-Offering for the people and bring the blood inside the curtain. He will repeat what he does with the bull’s blood, sprinkling it on and before the Atonement-Cover. In this way he will make atonement for the Holy of Holies because of the uncleannesses of the Israelites, their acts of rebellion, and all their other sins. He will do the same thing for the Tent of Meeting which dwells among the people in the midst of their uncleanness. There is to be no one in the Tent of Meeting from the time Aaron goes in to make atonement in the Holy of Holies until he comes out, having made atonement for himself, his household, and the whole community of Israel.