1 Chronicles 23:2-6
2 He also gathered together all the leaders of Israel, as well as the priests and Levites.
3 The Levites thirty years old or more were counted, and the total number of men was thirty-eight thousand.
4 David said, “Of these, twenty-four thousand are to supervise the work of the temple of the Lord and six thousand are to be officials and judges.
5 Four thousand are to be gatekeepers and four thousand are to praise the Lord with the musical instruments I have provided for that purpose.”
6 David divided the Levites into groups corresponding to the sons of Levi: Gershon, Kohath and Merari.