Numbers 18:2-7

²And take to yourself your brethren the tribe of Levi, the family of your father, and let them be joined to you, and let them minister to you; and you and your sons with you shall minister before the tabernacle of witness.

³And they shall keep your charges, and the charges of the tabernacle; only they shall not approach the holy vessels and the altar, so both they and you shall not die.

⁴And they shall be joined to you, and shall keep the charges of the tabernacle of witness, in all the services of the tabernacle; and a stranger shall not approach to you.

⁵And you° shall keep the charges of the holy things, and the charges of the altar, and so there shall not be anger amongst the children of Israel.

⁶And I have taken your brethren the Levites out of the midst of the children of Israel, a present given to the Lord, to minister in the services of the tabernacle of witness.

⁷And you and your sons after you shall keep up your priestly ministration, according to the whole manner of the altar, and that which is within the veil; and you° shall minister in the services as the office of your priesthood; and the stranger that comes near shall die.