Numbers 3:40-43

Then the LORD said to Moses, “Number every firstborn male of the Israelites from a month old and upward, and make a list of their names. You 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.” So Moses numbered all the firstborn among the Israelites, just as the LORD had commanded him; and all the firstborn males from a month old and upward as numbered were 22,273 [273 more than the Levites].