Numbers 3:46-51

46And as the redemption price for the 273 of the firstborn of the people of Israel, over and above the number of the male Levites,

47you shall take five shekels per head; you shall take them according to the shekel of the sanctuary (the shekel of twenty gerahs),

48and give the money to Aaron and his sons as the redemption price for those who are over."

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

50From the firstborn of the people of Israel he took the money, 1,365 shekels, by the shekel of the sanctuary.

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