Numbers 18:26 in the King James Version
Thus speak unto the Levites, 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 up an heave offering of it for the LORD, even a tenth part of the tithe.
Context
25 The LORD spoke to Moses, saying,
26 “Moreover you shall speak to the Levites, and tell them, ‘When you take of the children of Israel the tithe which I have given you from them for your inheritance, then you shall offer up a wave offering of it for the LORD, a tithe of the tithe.
27 Your wave offering shall be credited to you, as though it were the grain of the threshing floor, and as the fullness of the wine press.