The Price For Redemption of a Beast (Leviticus 27:9-13).
“And if it be a beast, of which men offer an oblation to Yahweh, all that any man gives of such to Yahweh shall be holy. He shall not alter it, nor change it, a good for a bad, or a bad for a good: and if he shall at all change beast for beast, then both it and that for which it is changed shall be holy.”
Any clean and sacrificial beast vowed to Yahweh was holy. Once offered it could not be changed, whether for better of for worse. If one was replaced then both became holy to Yahweh. This being the case we would assume that the purpose of replacing it was in order to offer something more worthy of Yahweh. Yahweh will receive two offerings instead of one. But neither can be redeemed. One example of such would be a whole burnt offering.
“And if it be any unclean beast, of which they do not offer an oblation to Yahweh, then he shall set the beast before the priest; and the priest shall value it, whether it be good or bad: as you the priest value it, so shall it be. But if he will indeed redeem it, then he shall add the fifth part of it to your estimation.”
Where the beast that is vowed to Yahweh is an unclean beast, possibly an ass or a camel, it can be redeemed at a price put on it by the priest. And he must add one fifth of the valuation as recompense. He has offered to Yahweh in his vow something which was of great importance to him. He wanted to give something that he treasured. Now he gladly pays a higher price to the Sanctuary in order to receive it back and in order to demonstrate his love for God. This is a somewhat similar case to the first born of an ass which must be redeemed, or its neck broken as a gift to Yahweh (Exodus 13:2; Exodus 13:13) although there the price of redemption was a lamb and it was always required.