1 Chronicles 23:2-11

At the same time he brought together all the leaders of Israel, the priests, and the Levites. The Levites thirty years and older were counted; the total was thirty-eight thousand. David sorted them into work groups: “Twenty-four thousand are in charge of administering worship in the sanctuary; six thousand are officials and judges; four thousand are security guards; and four thousand are to serve in the orchestra, praising GOD with instruments that I have provided for praise.” David then divided the Levites into groupings named after the sons of Levi: Gershon, Kohath, and Merari. The Gershonites: Ladan and Shimei. The three sons of Ladan: Jehiel, Zetham, and Joel. The three sons of Shimei: Shelomoth, Haziel, and Haran, all heads of the families of Ladan. The four sons of Shimei: Jahath, Ziza, Jeush, and Beriah. Jahath came first, followed by Ziza. Jeush and Beriah did not have many sons so they were counted as one family with one task.