Leviticus 27:31-33

American Standard Version

³¹ And if a man will redeem aught of his tithe, he shall add unto it the fifth part thereof. ³² And all the tithe of the herd or the flock, whatsoever passeth under the rod, the tenth shall be holy unto Jehovah. ³³ 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.