These last few verses need some clarification.
1Sa 19:19 And it was told Saul, saying, Behold, David is at Naioth in Ramah.
1Sa 19:20 And Saul sent messengers to take David: and when they saw the company of the prophets prophesying, and Samuel standing as appointed over them, the Spirit of God was upon the messengers of Saul, and they also prophesied.
and when they saw the company of the prophets prophesying; or praising, as the Targum; singing hymns and songs of praise to God, under the inspiration and influence of the Spirit of God, who endited these songs for them, and excited them to sing them; these prophets belonged to the school or college of prophets at Naioth, whom the messengers saw when they came thither, and found them thus employed; or “when he saw” (m), for the word is singular, that is, the chief of the messengers, or everyone of them, so Kimchi:
and Samuel standing as appointed over them; he was president of the college, and he stood to instruct and teach them in the knowledge of divine things: so the Targum,”standing, teaching over them or by them,”and to direct and assist them in singing their songs of praise:
the Spirit of the Lord was upon the messengers of Saul, and they also prophesied: or praised, as the Targum; sung hymns and songs of praise as the prophets did, and were so taken up with these religious exercises, that they forgot, or were inattentive to the business they were sent to do. Ben Gersom thinks they foretold things to come, and so Abarbinel; and particularly that they prophesied that David should rule over all Israel, and that God would not suffer Saul to slay him; and so were indifferent to, and negligent of doing the errand they were sent on, yea, purposely avoided it.
1Sa 19:21 And when it was told Saul, he sent other messengers, and they prophesied likewise. And Saul sent messengers again the third time, and they prophesied also.
and Saul sent messengers again a third time, and they prophesied also; joined the rest in singing praises, or foretelling future events.
1Sa 19:22 Then went he also to Ramah, and came to a great well that is in Sechu: and he asked and said, Where are Samuel and David? And one said, Behold, they be at Naioth in Ramah.
1Sa 19:23 And he went thither to Naioth in Ramah: and the Spirit of God was upon him also, and he went on, and prophesied, until he came to Naioth in Ramah.
and he went on and prophesied until he came to Naioth in Ramah: in this he differed from his messengers; they did not prophesy till they came to that place, but Saul began to prophesy before he came thither, as he was in his way from the well to it.
1Sa 19:24 And he stripped off his clothes also, and prophesied before Samuel in like manner, and lay down naked all that day and all that night. Wherefore they say, Is Saul also among the prophets?
and prophesied before Samuel in like manner, as the messengers had done, singing such like songs, or foretelling such like things as they did; he and they speaking not of themselves, but as they were moved by the Holy Spirit of prophecy; for such gifts have sometimes been bestowed on men that were destitute of the grace of God, as Balaam, Caiaphas, and others: