Numbers 3:12,41,45
And I, behold, I have taken the Levites from among the children of Israel instead of all the firstborn that opens the matrix among the children of Israel: therefore the Levites shall be mine;
Nave's Topical Index—AKJV

Numbers 8:18
And I have taken the Levites for all the firstborn of the children of Israel.
Nave's Topical Index—AKJV