Numbers 18:26-32

26Thus speak to the Levites, and say to them, When ye take of the children of Israel the tithes which I have given you from them for your inheritance, then ye shall offer up an heave offering of it for the LORD, even a tenth part of the tithe. 27And this your heave offering shall be reckoned to you, as though it were the grain of the threshingfloor, and as the fulness of the winepress. 28Thus ye also shall offer an heave offering to the LORD of all your tithes, which ye receive of the children of Israel; and ye shall give of them the LORD’S heave offering to Aaron the priest. 29Out of all your gifts ye shall offer every heave offering of the LORD, of all the best of it, even the hallowed part from it.1 30Therefore thou shalt say to them, When ye have offered the best of it, then it shall be counted to the Levites as the increase of the threshingfloor, and as the increase of the winepress.2 31And ye shall eat it in every place, ye and your households: for it is your reward for your service in the tabernacle of the congregation. 32And ye shall bear no sin by reason of it, when ye have offered from it the best of it: neither shall ye pollute the holy things of the children of Israel, lest ye die.