Numbers 3:40-51

Then the LORD said to Moses, “Now count all the firstborn sons in Israel who are one month old or older, and make a list of their names. The Levites must be reserved for me as substitutes for the firstborn sons of Israel; I am the LORD. And the Levites’ livestock must be reserved for me as substitutes for the firstborn livestock of the whole nation of Israel.” So Moses counted the firstborn sons of the people of Israel, just as the LORD had commanded. The number of firstborn sons who were one month old or older was 22,273. Then the LORD said to Moses, “Take the Levites as substitutes for the firstborn sons of the people of Israel. And take the livestock of the Levites as substitutes for the firstborn livestock of the people of Israel. The Levites belong to me; I am the LORD. There are 273 more firstborn sons of Israel than there are Levites. To redeem these extra firstborn sons, collect five pieces of silver for each of them (each piece weighing the same as the sanctuary shekel, which equals twenty gerahs). Give the silver to Aaron and his sons as the redemption price for the extra firstborn sons.” So Moses collected the silver for redeeming the firstborn sons of Israel who exceeded the number of Levites. He collected 1,365 pieces of silver on behalf of these firstborn sons of Israel (each piece weighing the same as the sanctuary shekel). And Moses gave the silver for the redemption to Aaron and his sons, just as the LORD had commanded.