Leviticus 27:30-33

And all the tithe of the land, whether of the seed of the land, or of the fruit of the tree, is the LORD'S: it is holy unto the LORD. And if a man will redeem aught of his tithe, he shall add unto it the fifth part thereof. And all the tithe of the herd or the flock, whatsoever passeth under the rod, the tenth shall be holy unto the LORD. He shall not search whether it be good or bad, neither shall he change it: and if he change it at all, then both it and that for which it is changed shall be holy; it shall not be redeemed.