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.
Moreover David and the captains of the host separated to the service those of the sons of Asaph, and of Heman, and of Jeduthun, who should prophesy with harps, with psalteries, and with cymbals: and the number of the men who served according to their service was:
And the priests served in their offices: the Levites also with instruments of music of the LORD, which David the king had made to praise the LORD, because his mercy endures for ever, when David praised by means of their ministry; and the priests sounded trumpets before them, and all Israel stood.