Leviticus 16:1-3

Living Bible

16 ^1-2 After Aaron’s two sons died before the Lord, the Lord said to Moses, “Warn your brother Aaron not to enter into the Holy Place behind the veil, where the Ark and the place of mercy are, just whenever he chooses. The penalty for intrusion is death. For I myself am present in the cloud above the place of mercy.

³ “Here are the conditions for his entering there: He must bring a young bull for a sin offering, and a ram for a burnt offering.