Leviticus 27:30-33

30‘Now 1all the tithe of the land, of the seed of the land or of the fruit of the tree, is the Lord’s; it is holy to the Lord. 31If, therefore, someone should ever want to redeem part of his tithe, he shall add to it a fifth of it. 32For every tenth part of herd or flock, whatever 2passes under the rod, the tenth one shall be holy to the Lord. 333He is not to be concerned whether it is good or bad, nor shall he exchange it; yet if he does exchange it, then both it and its substitute shall become holy. It shall not be redeemed.’”