Leviticus 27:27

27:27 If, however, it is among the unclean animals, he may ransom it according to its conversion value and must add one fifth to it, but if it is not redeemed it must be sold according to its conversion value.

Leviticus 27:33

27:33 The owner must not examine the animals to distinguish between good and bad, and he must not exchange it. If, however, he does exchange it, both the original animal and its substitute will be holy. It must not be redeemed.’”