Numbers 3:9
And you shall give the Levites to Aaron and to his sons: they are wholly given to him out of the children of Israel.
Torrey's Topical Textbook—AKJV

Numbers 8:19
And I have given the Levites as a gift to Aaron and to his sons from among the children of Israel, to do the service of the children of Israel in the tabernacle of the congregation, and to make an atonement for the children of Israel: that there be no plague among the children of Israel, when the children of Israel come near to the sanctuary.
Torrey's Topical Textbook—AKJV