And concerning the tithe of the herd or the flock, of whatever passes under the rod, the tenth one shall be holy to the LORD.
Leviticus 27:32
Surrounding context
27:31 If a man wants at all to redeem any of his tithes, he shall add one-fifth to it.
27:32 And concerning the tithe of the herd or the flock, of whatever passes under the rod, the tenth one shall be holy to the LORD.
27:33 He shall not inquire whether it is good or bad, nor shall he exchange it; and if he exchanges it at all, then both it and the one exchanged for it shall be holy; it shall not be redeemed."'