Numbers 18:30-32

30And thou shalt say unto them, When ye heave the best thereof from it, then it shall be counted unto the Levites as produce of the threshing-floor, and as produce of the winepress. 31And ye shall eat it in every place, ye and your households; for it is your reward for your service in the tent of meeting. 32And ye shall bear no sin by reason of it, if ye heave from it the best of it; and ye shall not profane the holy things of the children of Israel, lest ye die.