Leviticus 27:26-27 - Redemption Of The Firstborn
26 " 'However, a man shall not consecrate a firstborn among livestock, which belongs as firstborn to Yahweh; whether an ox {or} small livestock, it is for Yahweh. 27 And if [it is] among the unclean animals, then he shall ransom [it] according to your proper value, and he shall add a fifth of its [value] onto it; and if it is not redeemed, then it shall be sold according to your proper value.
40 And Yahweh said to Moses, "Muster every firstborn male from the {Israelites} from {one month} and above and {count} their names. 41 And you will receive the Levites for me--I [am] Yahweh--in the place of all [the] firstborn among the {Israelites}, and the animals of the Levites in the place of all [the] firstborn among the animals among the {Israelites}." 42 So Moses mustered all the firstborn among the {Israelites} just as Yahweh commanded him. 43 And all [the] firstborn males among the number of names from {one month} and above, the {ones counted}, [were] twenty-two thousand two hundred and seventy-three.
44 Yahweh spoke to Moses, saying, 45 "Receive the Levites in the place of all [the] firstborn among the {Israelites}, and the animals of the Levites in the place of their animals; the Levites will be mine. I [am] Yahweh.
46 And the ransom of the two hundred and seventy-three of the firstborn of the {Israelites} who are excessive over the Levites, 47 you will receive five shekels a person, in the sanctuary shekel; you will collect twenty gerahs [per] shekel. 48 You will give the money to Aaron, and to his sons the ransom of the ones who are excessive among them."
49 And Moses received the money of the redemption from the ones who were excessive from those redeemed of the Levites. 50 From the firstborn of the {Israelites} he took the money, one thousand three hundred and sixty-five shekels, in the sanctuary shekel. 51 And Moses gave the money of the ransom to Aaron and to his sons according to the {word} of Yahweh just as Yahweh commanded Moses.