1 Chronicles

And he appointed, according to the order of David his father, the courses of the priests to their service, and the Levites to their charges, to praise and minister before the priests, as the duty of every day required: the porters also by their courses at every gate: for so had David the man of God commanded.

The sons of Levi; Gershon, Kohath, and Merari.

And he set the Levites in the house of the Lord with cymbals, with psalteries, and with harps, according to the commandment of David, and of Gad the king’s seer, and Nathan the prophet: for so was the commandment of the Lord by his prophets.

And they set the priests in their divisions, and the Levites in their courses, for the service of God, which is at Jerusalem; as it is written in the book of Moses.

The sons of Levi; Gershom, Kohath, and Merari.