The Sharia of Moses in the TORA
Part 1 - The 248 Positive Commandments of the Tora
129 - THE LEVITES' TITHE FOR THE PRIESTS
Scripture points out that the Levites commit a transgression if they do not select the heave offering from the best part of the tithe.
The heave-offering of the tithe which was given by the Levites to the priest was in all respects as holy as the great heave-offering given by the Israelite to the priest. A non-priest who ate either of them willfully incurred the penalty of death by the hand of Heaven; if he ate either of them unintentionally, he was obliged to make restitution, adding a fifth to the valuation. Neither the heave-offering of the tithe nor the great heave-offering was to be eaten in a state of uncleanness.*