Numbers 18:27-28

²⁷And your heave-offering shall be reckoned unto you, as the corn from the threshing-floor, and as the fulness of the winepress.

²⁸Thus ye also shall offer Jehovah's heave-offering of all your tithes, which ye take of the children of Israel; and ye shall give thereof Jehovah's heave-offering to Aaron the priest.