I Chronicles 23:30

And that they should keep the charge of the tabernacle of the congregation,.... That no unclean persons entered into it, and that none of the vessels were carried out of it; this was the business of the porters: and the charge of the holy place; of things that belonged unto it, the vessels in it, and what was requisite for it, and used there: and the charge of the sons of Aaron their brethren; the priests, whatever they should command them to do: in the service of the house of the Lord; in any part and branch of it before specified. Next: 1 Chronicles Chapter 24

David, having given charge concerning the building of the temple, in this and the following chapters settles the method of the temple-service and puts into order the offices and officers of it. In the late irregular times, and during the wars in the beginning of his reign, we may suppose that, though the Levitical ordinances were kept up, yet it was not in the order, nor with the beauty and exactness, that were desirable. Now David, being a prophet, as well as a prince, by divine warrant and direction, "set in order the things that were wanting." In this chapter we are informed, I. He declared Solomon to be his successor, (Ch1 23:1). II. He numbered the Levites, and appointed them to their respective offices (Ch1 23:2-5). III. He took an account of the several families of the Levites (v. 6-23). IV. He made a new reckoning of them from twenty years old, and appointed them their work (Ch1 23:24-32). And in this he prepared for the temple as truly as when he laid up gold and silver for it; for the place is of small account in comparison with the work.