Leviticus 27:29-27:34
No human being who has been proscribed can be ransomed: he shall be put to death.
All tithes from the land, whether seed from the ground or fruit from the tree, are the Lord's; they are holy to the Lord. If anyone wishes to redeem any of his tithes, he must add one-fifth to them. All tithes of the herd or flock--of all that passes under the shepherd's staff, every tenth one--shall be holy to the Lord. He must not look out for good as against bad, or make substitution for it. If he does make substitution for it, then it and its substitute shall both be holy: it cannot be redeemed.
These are the commandments that the Lord gave Moses for the Israelite people on Mount Sinai.