Numbers 3:40-45

Redemption of the Firstborn

40 Then Yahweh said to Moses, “^aNumber every firstborn male of the sons of Israel from a month old and upward, and ¹make a list of their names. 41 And you ^ashall take the Levites for Me, I am Yahweh, instead of all the firstborn among the sons of Israel, and the cattle of the Levites instead of all the firstborn among the cattle of the sons of Israel.” 42 So Moses numbered all the firstborn among the sons of Israel, just as Yahweh had commanded him; 43 and all the firstborn males by the number of names from a month old and upward, for their numbered men were ^a22,273.
44 Then Yahweh spoke to Moses, saying, 45 “^aTake the Levites instead of all the firstborn among the sons of Israel and the cattle of the Levites. And the Levites shall be Mine; I am Yahweh.