Numbers 3:40-51
The firstborn sons belong to the Lord
40 The Lord said to Moses, ‘Record all the firstborn sons of the Israelites. Record every male who is one month old or older. Make a list of their names. 41 The Israelites' firstborn sons belong to me. I am the Lord. But I will accept all the males among the Levites instead. The Israelites' firstborn animals also belong to me. But I will accept the animals of the Levites instead.’
42 So Moses counted all the firstborn males among the Israelites as the Lord had said. 43 He counted 22,273 firstborn males who were one month old or older. He made a list of their names.
44 Then the Lord said to Moses, 45 ‘Do not take the firstborn males among the people to belong to me. Accept the Levites instead. Do not use the firstborn animals of the people. Accept the animals of the Levites instead. The Levites will belong to me. I am the Lord. 46 There are 273 more firstborn males of the people than there are Levites. So the people must pay for the extra firstborn sons. 47 You must accept five shekels for each extra firstborn male. The shekel must have the same weight as the shekel that the Levites use in God's tabernacle. There are 20 gerahs in one shekel. 48 Give that money to Aaron and his sons.’
49 So Moses took the money to buy back the extra 273 firstborn sons. That was because the number of firstborn sons was more than the number of Levites. 50 He took 1,365 shekels from them. The shekels had the same weight as the shekel that the Levites used in God's tabernacle. 51 Moses did what the Lord had told him to do. He gave the money to Aaron and his sons.