Numbers 3:46-48

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.”