6 Also David separated them into divisions among the sons of Levi: Gershon, Kohath, and Merari. 7 Of the Gershonites: Laadan and Shimei. 8 The sons of Laadan: the first Jehiel, then Zetham and Joel--three in all. 9 The sons of Shimei: Shelomith, Haziel, and Haran--three in all. These were the heads of the fathers' houses of Laadan. 10 And the sons of Shimei: Jahath, Zina, Jeush, and Beriah. These were the four sons of Shimei. 11 Jahath was the first and Zizah the second. But Jeush and Beriah did not have many sons; therefore they were assigned as one father's house. 12 The sons of Kohath: Amram, Izhar, Hebron, and Uzziel--four in all. 13 The sons of Amram: Aaron and Moses; and Aaron was set apart, he and his sons forever, that he should sanctify the most holy things, to burn incense before the Lord, to minister to Him, and to give the blessing in His name forever.
Matthew Henry's Commentary on 1 Chronicles 23:6-13
Commentary on 1 Chronicles 23:1-23
(Read 1 Chronicles 23:1-23)
David, having given charge concerning the building of the temple, settles the method of the temple service, and orders the officers of it. When those of the same family were employed together, it would engage them to love and assist one another.