Numbers 18:2; Numbers 18:6

2 And with you bring your brothers 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.

6 And behold, I have taken your brothers the Levites from among the people of Israel. They are a gift to you, given to the LORD, to do the service of the tent of meeting.