Numbers 18:24-27

²⁴for I have given for an inheritance to the Levites the tithes of the children of Israel, which they offer as a heave-offering to Jehovah; therefore I have said of them, They shall possess no inheritance among the children of Israel.

²⁵And Jehovah spoke to Moses, saying,

²⁶And to the Levites shalt thou speak, and say unto 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 a heave-offering from it for Jehovah, the tenth of the tithe.

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