1 Chronicles 23:2-6

ISV(i) 2 David then gathered together all of the leaders of Israel, including the priests and descendants of Levi. 3 descendants of Levi 30 years old and above were counted for a total of 38,000. 4 “24,000 of these,” David said, “are to be set in charge of the work of the Temple of the LORD, with 6,000 serving as officers and judges, 5 with 4,000 gatekeepers, and with 4,000 offering praises to the LORD with the musical instruments that I have had crafted.”
6 David divided them into divisions based on Gershon, Kohath, and Merari, Levi’s sons.