C. F. Keil and Franz Delitzsch on 1 Chronicles 23:2

1Ch 23:2 Numbering of the Levites, and partition of their duties. - 1Ch 23:2. For this purpose David collected “all the princes of Israel, and the priests and Levites.” The princes of Israel, because the numbering of the Levites and the determination of their duties was a matter of national importance. “The meaning is, that David, in a solemn assembly of the princes, i.e., of the representatives of the lay tribes, and of the priests and Levites, fixed the arrangements of which an account is to be given” (Berth.).