Leviticus 27:29

25 Every valuation will be according to the sanctuary shekel, twenty gerahs to the shekel.

26 But no one may consecrate a firstborn of the livestock, because a firstborn belongs to the LORD. Whether it is an ox or a sheep, it is the LORD’s.

27 But if it is among the unclean animals, then he may redeem it according to your valuation and add a fifth of its value. If it is not redeemed, then it shall be sold according to your valuation.

28 Nothing that a man sets apart to the LORD from all he owns—whether a man, an animal, or his inherited land—can be sold or redeemed; everything so devoted is most holy to the LORD.

29 No person set apart for destruction may be ransomed; he must surely be put to death.

30 Thus any tithe from the land, whether from the seed of the land or the fruit of the trees, belongs to the LORD; it is holy to the LORD.

31 If a man wishes to redeem part of his tithe, he must add a fifth to its value.

32 Every tenth animal from the herd or flock that passes under the shepherd’s rod will be holy to the LORD.

33 He must not inspect whether it is good or bad, and he shall not make any substitution. But if he does make a substitution, both the animal and its substitute shall become holy; they cannot be redeemed.’”

Read all of Leviticus 27