Numbers 18:21,24
And, behold, I have given the children of Levi all the tenth in Israel for an inheritance, for their service which they serve, even the service of the tabernacle of the congregation.
Torrey's Topical Textbook—AKJV

2 Chronicles 31:4,5
Moreover he commanded the people that dwelled in Jerusalem to give the portion of the priests and the Levites, that they might be encouraged in the law of the LORD.
Torrey's Topical Textbook—AKJV

Nehemiah 12:44,45
And at that time were some appointed over the chambers for the treasures, for the offerings, for the first fruits, and for the tithes, to gather into them out of the fields of the cities the portions of the law for the priests and Levites: for Judah rejoiced for the priests and for the Levites that waited.
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