Numbers 18:6

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

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

— Numbers 18:6 —

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

⁸And the Lord said to Aaron, And, behold, I have given you the charge of the firstfruits of all things consecrated to me by the children of Israel; and I have given them to thee as an honor, and to thy sons after thee for a perpetual ordinance.