Leviticus 27:23-28

²³then the priest shall reckon to him the worth of your valuation up to the Year of Jubilee; and he shall give your valuation on that day, as a holy thing to the LORD.

²⁴In the Year of Jubilee the field shall return to him from whom it was bought, even to him to whom the possession of the land belongs.

²⁵All your valuations shall be according to the shekel of the sanctuary: twenty gerahs to the shekel.

²⁶“‘However the firstborn amongst animals, which belongs to the LORD as a firstborn, no man may dedicate, whether an ox or a sheep. It is the LORD’s.

²⁷If it is an unclean animal, then he shall buy it back according to your valuation, and shall add to it the fifth part of it; or if it isn’t redeemed, then it shall be sold according to your valuation.

²⁸“‘Notwithstanding, no devoted thing that a man devotes to the LORD of all that he has, whether of man or animal, or of the field of his possession, shall be sold or redeemed. Everything that is permanently devoted is most holy to the LORD.