Numbers 3:46-51

46And for those that are to be redeemed of the two hundred and threescore and thirteen of the firstborn of the children of Israel, which are more than the Levites;

47Thou shalt even take five shekels apiece by the poll, after the shekel of the sanctuary shalt thou take them: (the shekel is twenty gerahs:)

48And thou shalt give the money, wherewith the odd number of them is to be redeemed, unto Aaron and to his sons.

49And Moses took the redemption money of them that were over and above them that were redeemed by the Levites:

50Of the firstborn of the children of Israel took he the money; a thousand three hundred and threescore and five shekels, after the shekel of the sanctuary:

51And Moses gave the money of them that were redeemed unto Aaron and to his sons, according to the word of Yhwh, as Yhwh commanded Moses.