Numbers 18:6-8

Living Bible

⁶ I say it again—your kinsmen the Levites are your assistants for the work of the Tabernacle. They are a gift to you from the Lord. ⁷ But you and your sons, the priests, shall personally handle all the sacred service, including the altar and all that is within the veil, for the priesthood is your special gift of service. Anyone else who attempts to perform these duties shall die.”

⁸ The Lord gave these further instructions to Aaron: “I have given the priests all the gifts which are brought to the Lord by the people; all these offerings presented to the Lord by the gesture of waving them before the altar belong to you and your sons, by permanent law.