6 And David divided them into courses according to the sons of Levi: Gershon, Kohath, and Merari. 7 Of the Gershonites: Laadan and Shimei. 8 The sons of Laadan: the head was Jehiel, and Zetham, and Joel, three. 9 The sons of Shimei: Shelomith, and Haziel, and Haran, three. These were the chief fathers of Laadan. 10 And the sons of Shimei: Jahath, Ziza, and Jeush, and Beriah. These were the four sons of Shimei. 11 And Jahath was the head, and Ziza the second; and Jeush and Beriah had not many sons: as father's house, therefore, they were reckoned as one. 12 The sons of Kohath: Amram, Jizhar, Hebron, and Uzziel, four. 13 The sons of Amram: Aaron and Moses. And Aaron was separated, that he should be hallowed as most holy, he and his sons for ever, to offer before Jehovah, to do service to him, and to bless in his name for ever.
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.