Numbers 3:44-51

44Then the Lord spoke to Moses, saying:

45“Take the Levites instead of all the firstborn among the children of Israel, and the livestock of the Levites instead of their livestock. The Levites shall be Mine: I am the Lord.

46And for the redemption of the two hundred and seventy-three of the firstborn of the children of Israel, who are more than the number of the Levites,

47you shall take five shekels for each one individually; you shall take them in the currency of the shekel of the sanctuary, the shekel of twenty gerahs.

48And you shall give the money, with which the excess number of them is redeemed, to Aaron and his sons.”

49So Moses took the redemption money from those who were over and above those who were redeemed by the Levites.

50From the firstborn of the children of Israel he took the money, one thousand three hundred and sixty-five shekels, according to the shekel of the sanctuary.

51And Moses gave their redemption money to Aaron and his sons, according to the word of the Lord, as the Lord commanded Moses.