Numbers 18:2-4

Revised Standard Version

² And with you bring your brethren also, the tribe of Levi, the tribe of your father, that they may join you, and minister to you while you and your sons with you are before the tent of the testimony. ³ They shall attend you and attend to all duties of the tent; but shall not come near to the vessels of the sanctuary or to the altar, lest they, and you, die. ⁴ They shall join you, and attend to the tent of meeting, for all the service of the tent; and no one else shall come near you.