Leviticus 27:31-33

New International Version - UK

³¹ Whoever would redeem any of their tithe must add a fifth of the value to it. ³² Every tithe of the herd and flock – every tenth animal that passes under the shepherd’s rod – will be holy to the Lord. ³³ No one may pick out the good from the bad or make any substitution. If anyone does make a substitution, both the animal and its substitute become holy and cannot be redeemed.”’