Numbers 18:1-7 - Provision For The Priesthood
1 And the LORD said unto Aaron, Thou and thy sons and thy father's house with thee shall bear the iniquity of the sanctuary; and thou and thy sons with thee shall bear the iniquity of your priesthood. 2 And thy brethren also of the tribe of Levi, the tribe of thy father, bring thou with thee, that they may be joined unto thee and serve thee; but thou and thy sons with thee shall serve before the tabernacle of the testimony. 3 And they shall keep thy charge, and the charge of all the tabernacle; only they shall not come near the holy vessels or the altar, that neither they, nor ye also, die. 4 And they shall join themselves unto thee and keep the charge of the tabernacle of the testimony in all the service of the tabernacle; and no stranger shall come near unto you.
5 And ye shall have the charge of the sanctuary and the charge of the altar, that there be no more wrath upon the sons of Israel. 6 For behold, I have taken your brethren the Levites from among the sons of Israel, given unto you as a gift of the LORD, to serve in the ministry of the tabernacle of the testimony. 7 Therefore thou and thy sons with thee shall keep your priesthood for every thing of the altar and within the veil, and ye shall minister; for I have given the service of your priesthood as a gift, and the stranger that comes near shall die.