“Moreover David and the captains of the host separated to the service 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 workmen according to their service was:”
The singers were divided into 24 courses, so that every course or order contained twelve, and in all there were 288, as verse 7.
“Of Jeduthun: the sons of Jeduthun; Gedaliah, and Zeri, and Jeshaiah, Hashabiah, and Mattithiah, six, under the hands of their father Jeduthun, who prophesied with a harp, to give thanks and to praise the LORD. Zeri: or, Izri”
Meaning, Psalms and songs to praise God. Whereof one is not here numbered.
“All these were the sons of Heman the king's seer in the words of God, to lift up the horn. And God gave to Heman fourteen sons and three daughters. words: or, matters”
Or, Prophet. Or, power, meaning of the king.
“All these were under the hands of their father for song in the house of the LORD, with cymbals, psalteries, and harps, for the service of the house of God, according to the king's order to Asaph, Jeduthun, and Heman. according: Heb. by the hands of the king”
Hebrew, hand . Or, government.
“And they cast lots, ward against ward, as well the small as the great, the teacher as the scholar.”
Who should be in every company and course. Without respect to age or cunning.
“Now the first lot came forth for Asaph to Joseph: the second to Gedaliah, who with his brethren and sons were twelve :”
So that he served in the first turn, and the rest everyone as his turn followed orderly.