Números 3:41

41 Take the Levites for me in place of all the firstborn of the Israelites, and the livestock of the Levites in place of all the firstborn of the livestock of the Israelites. I am the Lord."

41 And give to me the Levites (I am the Lord) in place of the first sons of the children of Israel; and the cattle of the Levites in place of the first births among the cattle of the children of Israel.