Malachi 2:4

2:4 Then you will know that I sent this commandment to you so that my covenant may continue to be with Levi,” says the Lord who rules over all.

Malachi 2:7

2:7 For the lips of a priest should preserve knowledge of sacred things, and people should seek instruction from him because he is the messenger of the Lord who rules over all.

Malachi 3:3

3:3 He will act like a refiner and purifier of silver and will cleanse the Levites and refine them like gold and silver. Then they will offer the Lord a proper offering.