Verse 2. "Which prophesied" - Sunghymns and prayed. But the Targum understands this of prophesying in the proper sense of the term; and therefore says, "Who prophesied by the Holy Spirit." Jarchi is of the same opinion and quotes the case of Elisha, 2 Kings iii. 15; While the minstrel played, the hand of the Lord [i.e., the spirit of prophecy] was upon him.
Verse 3. "The sons of Jeduthun-six" - That is, six with their father, otherwise, there are but five. Hence it is said, they were under the hands of their father Jeduthun, who prophesied with a harp, &c.