Numbers 8:10

8:10 Then you are to bring the Levites before the Lord, and the Israelites are to lay their hands on the Levites;

Numbers 8:14

8:14 And so you are to separate the Levites from among the Israelites, and the Levites will be mine.

Numbers 1:47

The Exemption of the Levites

1:47 But the Levites, according to the tribe of their fathers, were not numbered among them.