Leviticus 27:26-27 - Redemption Of The Firstborn
26 But the firstborn of the animals, which because it is firstborn belongs to the LORD, no one shall sanctify it; whether it is ox or sheep, it is the LORD's. 27 And if it is of an unclean beast, it shall be ransomed according to thy estimation, and they shall add a fifth part unto it; or if it is not redeemed, then it shall be sold according to thy estimation.
40 And the LORD said unto Moses, Number all the firstborn of the males of the sons of Israel from a month old and upward and take the number of their names. 41 And thou shalt take the Levites for me (I am the LORD) instead of all the firstborn among the sons of Israel and the animals of the Levites instead of all the firstborn among the animals of the sons of Israel. 42 And Moses numbered, as the LORD commanded him, all the firstborn among the sons of Israel. 43 And all the firstborn males by the number of names, from a month old and upward, of those that were numbered of them, were twenty-two thousand two hundred seventy-three.
44 And the LORD spoke unto Moses, saying, 45 Take the Levites instead of all the firstborn among the sons of Israel and the animals of the Levites instead of their animals, and the Levites shall be mine; I am the LORD.
46 And for the ransoms of the two hundred seventy-three of the firstborn of the sons of Israel, who are more than the Levites, 47 thou shalt take five shekels apiece by the poll, after the shekel of the sanctuary shalt thou take them (the shekel is of twenty gerahs). 48 And thou shalt give the money, of the ransoms of the odd number of them, unto Aaron and to his sons.
49 And Moses took the ransom money of those that were over and above the ones that were redeemed by the Levites 50 and received of the firstborn of the sons of Israel, in money, a thousand three hundred and sixty-five shekels, after the shekel of the sanctuary. 51 And Moses gave the money of the ransoms unto Aaron and to his sons, according to the word of the LORD, as the LORD had commanded Moses.