Leviticus 27:26-27 - Redemption Of The Firstborn
26 Only the firstling among beasts, which is made a firstling to LORD, no man shall sanctify it, whether it be ox or sheep, it is LORD's. 27 And if it be of an unclean beast, then he shall ransom it according to thine estimation, and shall add to it the fifth part of it, or if it be not redeemed, then it shall be sold according to thy estimation.
40 And LORD said to Moses, Number all the first-born males of the sons of Israel from a month old and upward, and take the number of their names. 41 And thou shall take the Levites for me (I am LORD) instead of all the first-born among the sons of Israel, and the cattle of the Levites instead of all the firstlings among the cattle of the sons of Israel. 42 And Moses numbered, as LORD commanded him, all the first-born among the sons of Israel. 43 And all the first-born males according to the number of names, from a month old and upward, of those who were numbered of them, were twenty-two thousand two hundred and seventy-three.
44 And LORD spoke to Moses, saying, 45 Take the Levites instead of all the first-born among the sons of Israel, and the cattle of the Levites instead of their cattle. And the Levites shall be mine. I am LORD.
46 And for the redemption of the two hundred and seventy-three of the first-born of the sons of Israel, who are over and above [the number of] the Levites, 47 thou shall take five shekels apiece by the poll. According to the shekel of the sanctuary thou shall take them (the shekel is twenty gerahs), 48 and thou shall give the money, with which the odd number of them is redeemed, to Aaron and to his sons.
49 And Moses took the redemption-money from those who were over and above those who were redeemed by the Levites. 50 He took the money from the first-born of the sons of Israel, a thousand three hundred and sixty-five [shekels], according to the shekel of the sanctuary. 51 And Moses gave the redemption-money to Aaron and to his sons, according to the word of LORD, as LORD commanded Moses.