Numbers 18:1-2

Young's Literal Translation

18 And Jehovah saith unto Aaron, `Thou, and thy sons, and the house of thy father with thee, do bear the iniquity of the sanctuary; and thou, and thy sons with thee, do bear the iniquity of your priesthood;

² and also thy brethren, the tribe of Levi, the tribe of thy father, bring near with thee, and they are joined unto thee, and serve thee, even thou and thy sons with thee, before the tent of the testimony.