Numbers 18:1-2

Amplified Bible, Classic Edition

18 And the Lord said to Aaron, You and your sons and your father’s house with you shall bear and remove the iniquity of the sanctuary [that is, the guilt for the offenses which the people unknowingly commit when brought into contact with the manifestations of God’s presence]. And you and your sons with you shall bear and remove the iniquity of your priesthood [your own unintentional offenses].

² And your brethren also of the tribe of Levi, the tribe of your [fore]father, bring with you, that they may be joined to you and minister to you; but only you and your sons with you shall come before the Tent of the Testimony [into the Holy Place where only priests may go and into the Most Holy Place which only the high priest dares enter].