Charles Ellicott Commentary 1 Samuel 19:21

"And when it was told Saul, he sent other messengers, and they also prophesied. And Saul sent messengers again the third time, and they also prophesied." — 1 Samuel 19:21 (ASV)

And they prophesied likewise. — Bishop Wordsworth calls attention here to the fact of “this portion of Scripture, from 1 Samuel 19:18 to the end of the chapter, which relates the coming upon of the Spirit on Saul’s messengers, and even on Saul himself, the persecutor of David, being appointed by the Church to be read on Whitsun Tuesday (Old Lect.), in order to show the existence and working of the Holy Spirit before the times of the Gospel, and the freedom and power of His Divine agency.” (Compare to Numbers 11:26-31: the history of Eldad and Medad, which we read on Whitsun Monday, New Lect.)