Numbers 3:41-45

41You shall take the Levites for Me instead of and as a substitute for all the firstborn among the Israelites. I am the Lord; and you shall take the cattle of the Levites instead of and as a substitute for all the firstborn among the cattle of the Israelites.”

42So Moses numbered all the firstborn among the Israelites, just as the Lord had commanded him;

43and all the firstborn males from a month old and upward as numbered were 22,273 [273 more than the Levites].

44Then the Lord spoke to Moses, saying,

45“Take the Levites [for Me] instead of all the firstborn among the sons of Israel, and the cattle of the Levites instead of their cattle. And the Levites shall be Mine. I am the Lord.