251 Moreover David and the captains of the host set apart for the service certain 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 them that did the work according to their service was:
Matthew Henry's Commentary on 1 Chronicles 25:1
The singers and musicians.
David put those in order who were appointed to be singers and musicians in the temple. To prophesy, in this place, means praising God with great earnestness and devout affections, under the influences of the Holy Spirit. In raising these affections, poetry and music were employed. If the Spirit of God do not put life and fervour into our devotions, they will, however ordered, be a lifeless, worthless form.