Leviticus 27:27-28

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.

Things Permanently Dedicated to the Lord

27:28 “‘Surely anything which a man permanently dedicates to the Lord from all that belongs to him, whether from people, animals, or his landed property, must be neither sold nor redeemed; anything permanently dedicated is most holy to the Lord.