Leviticus 27:30-33

30  a Every tithe of the land, whether of the seed of the land or of the fruit of the trees, is the  Lord’s; it is holy to the  Lord. 31 If a man wishes to redeem some of his tithe, he shall add a fifth to it. 32 And every tithe of herds and flocks, every tenth animal of all that b pass under the herdsman’s staff, shall be holy to the  Lord. 33 One shall not differentiate between good or bad, c neither shall he make a substitute for it; and if he does substitute for it, then both it and the substitute shall be holy; it shall not be redeemed.”

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