Jeremiah 33:21
19 The Lord’s message came to Jeremiah another time: 20 “I, the Lord, make the following promise: ‘I have made a covenant with the day and with the night that they will always come at their proper times. Only if you people could break that covenant 21 could my covenant with my servant David and my covenant with the Levites ever be broken. So David will by all means always have a descendant to occupy his throne as king and the Levites will by all means always have priests who will minister before me. 22 I will make the children who follow one another in the line of my servant David very numerous. I will also make the Levites who minister before me very numerous. I will make them all as numerous as the stars in the sky and as the sands that are on the seashore.’”
Malachi 2:4
2 If you do not listen and take seriously the need to honor my name,” says the Lord of Heaven’s Armies, “I will send judgment on you and turn your blessings into curses—indeed, I have already done so because you are not taking it to heart. 3 I am about to discipline your children and will spread offal on your faces, the very offal produced at your festivals, and you will be carried away along with it. 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 of Heaven’s Armies. 5 “My covenant with him was designed to bring life and peace. I gave its statutes to him to fill him with awe, and he indeed revered me and stood in awe before me. 6 He taught what was true; sinful words were not found on his lips. He walked with me in peace and integrity, and he turned many people away from sin.
Notes and References
"... The various texts of the Hebrew Bible that deal with the Levites are in agreement that the Levites are considered a group apart, separate from the other Israelite tribes or the rest of Israelite society. (Exodus 38:21; Leviticus 25:32-33; Deuteronomy 10:8-9; Joshua 13:14; Judges 17:19; Isaiah 66:21; Jeremiah 33:21-22; Ezekiel 45:5; Malachi 2:4; Ezra 3:8; Nehemiah 10:8) While any authentic historical reconstruction of the place of the Levites in ancient Israel, or the development of their role in society, is perhaps inaccessible with any degree of certainty, the traditional explanations for their separate status are present in a number of literary manifestations, particularly in the Pentateuch. The Priestly source attributes the separation of the Levites to a divine decree handed down at Sinai (Numbers 1–4), as it does for so many other phenomena, without any explanation for the choice of the Levites in particular ..."
Bade, Joel S. "The Violent Origins of the Levites: Text and Tradition" in Leuchter, Mark, et al. (eds.) Levites and Priests in Biblical History and Tradition (pp. 103-116) Society of Biblical Literature, 2011