Leviticus 27:26-27 - Redemption Of The Firstborn
26 Only the firstling of the beasts, which should be the LORD'S firstling, no man shall sanctify it; whether ox, or sheep: it is the LORD'S. 27 And if it shall be of an unclean beast, then he shall redeem it, according to thy estimation, and shall add to it a fifth part of it: or if it shall be not redeemed, then it shall be sold according to thy estimation.
40 And the LORD said to Moses, number all the first-born of the males of the children 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 first-born among the children of Israel; and the cattle of the Levites, instead of all the firstlings among the cattle of the children of Israel. 42 And Moses numbered, as the LORD commanded him, all the first-born among the children of Israel. 43 And all the first-born males by the number of names, from a month old and upward, of those that were numbered of them, were twenty and two thousand two hundred and seventy and three.
44 And the LORD spoke to Moses, saying, 45 Take the Levites instead of all the first-born among the children of Israel, and the cattle of the Levites instead of their cattle; and the Levites shall be mine: I am the LORD.
46 And for those that are to be redeemed of the two hundred and seventy and three, of the first-born of the children of Israel, which are more than the Levites: 47 Thou shalt even take five shekels apiece by the poll, after the shekel of the sanctuary shalt thou take them: the shekel is twenty gerahs. 48 And thou shalt give to Aaron and to his sons the money, with which the odd number of them is to be redeemed.
49 And Moses took the redemption-money of them that were over and above them that were redeemed by the Levites: 50 Of the first-born of the children of Israel he took the money; a thousand three hundred and sixty and five shekels, after the shekel of the sanctuary. 51 And Moses gave the money of them that were redeemed to Aaron, and to his sons, according to the word of the LORD, as the LORD commanded Moses.