Leviticus 27:30-33

30“Every tenth of the land’s produce, grain from the soil or fruit from the trees, belongs to the Lord; it is holy to the Lord.

31If a man decides to redeem any part of this tenth, he must add a fifth to its value.

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

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