Numbers 3:42-46

So Moses counted all the firstborn among the sons of Israel, just as the Lord had commanded him;

and all the firstborn males, by the number of names from a month old and upward for their numbered men, were 22,273.

Then the Lord spoke to Moses, saying,

“Take the Levites in place of all the firstborn among the sons of Israel, and the cattle of the Levites in place of their cattle. And the Levites shall be Mine; I am the Lord.

And as a redemption price for the 273 of the firstborn of the sons of Israel who are in excess of the number of the Levites,