Numbers 18:26

18:26 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 heave-offering of it for Yahweh, a tithe of the tithe.
-World English Bible

Other Translation

18:26 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.
-King James Version