Leviticus 27:30-34

“ ‘One-tenth of all crops belongs to the LORD, including the crops from fields and the fruit from trees. That one-tenth is holy to the LORD. If a person wants to get back that tenth, one-fifth must be added to its price. “ ‘The priest will take every tenth animal from a person’s herd or flock, and it will be holy to the LORD. The owner should not pick out the good animals from the bad or exchange one animal for another. If that happens, both animals will become holy; they cannot be bought back.’ ” These are the commands the LORD gave to Moses at Mount Sinai for the people of Israel.