6 And David distributeth them into courses: Of the sons of Levi: of Gershon, Kohath, and Merari. 7 Of the Gershonite: Laadan and Shimei. 8 Sons of Laadan: the head 'is' Jehiel, and Zetham, and Joel, three. 9 Sons of Shimei 'are' Shelomith, and Haziel, and Haran, three; these 'are' heads of the fathers of Laadan. 10 And sons of Shimei 'are' Jahath, Zina, and Jeush, and Beriah; these 'are' sons of Shimei, four. 11 And Jahath is the head, and Zizah the second, and Jeush and Beriah have not multiplied sons, and they become the house of a father by one numbering. 12 Sons of Kohath 'are' Amram, Izhar, Hebron, and Uzziel, four. 13 Sons of Amram: Aaron and Moses; and Aaron is separated for his sanctifying the holy of holies, he and his sons—unto the age, to make perfume before Jehovah, to serve Him, and to bless in His name—unto the age.
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.