Numbers 18:26,28
Thus speak to the Levites, and say to them, When you take of the children of Israel the tithes which I have given you from them for your inheritance, then you shall offer up an heave offering of it for the LORD, even a tenth part of the tithe.
Torrey's Topical Textbook—AKJV

Nehemiah 10:37,38
And that we should bring the first fruits of our dough, and our offerings, and the fruit of all manner of trees, of wine and of oil, to the priests, to the chambers of the house of our God; and the tithes of our ground to the Levites, that the same Levites might have the tithes in all the cities of our tillage.
Torrey's Topical Textbook—AKJV

Hebrews 7:5
And truly they that are of the sons of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people according to the law, that is, of their brothers, though they come out of the loins of Abraham:
Torrey's Topical Textbook—AKJV