Numbers 18:2-7

²And thy brethren also of the tribe of Levi, the tribe of thy father, bring with thee, and let them be added with thee, to serve thee; but thou and, thy sons with thee (shall minister) before the tabernacle of the testimony.

³And they shall keep thy charge, and the charge of all the tabernacle; but to the vessels of the sanctuary and of the altar they (the Levites) shall not approach, that neither they nor you may die.

⁴And they shall be joined, with thee, and keep charge of the tabernacle of ordinance for all the service of the tabernacle, and a stranger shall not come near you.

⁵And they shall keep charge of the sanctuary and of the altar, that there may be no more wrath upon the sons of Israel.

⁶And, behold, I have taken your brethren, the Levites, from among the sons of Israel; as a gift are they given to you before the Lord, to perform the service of the tabernacle of ordinance.

⁷But thou, and thy sons with thee, take charge of your priesthood, for everything about the altar and within the veil you shall fulfil the service; the ministry of the priesthood I have given you as a gift, and the stranger who cometh near shall die.