ButthesonsofRehabiahwereverymany - The Targum says, "On account of the merits of Moses, the posterity of Rehabiah were multiplied to more than sixty myriads."
Matthew Henry
Concise Bible Commentary
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.