20 he sent troops to capture him. But when they arrived and saw Samuel leading a group of prophets who were prophesying, the Spirit of God came upon Saul's men, and they also began to prophesy. 21 When Saul heard what had happened, he sent other troops, but they, too, prophesied! The same thing happened a third time. 22 Finally, Saul himself went to Ramah and arrived at the great well in Secu. "Where are Samuel and David?" he demanded. "They are at Naioth in Ramah," someone told him. 23 But on the way to Naioth in Ramah the Spirit of God came even upon Saul, and he, too, began to prophesy all the way to Naioth! 24 He tore off his clothes and lay naked on the ground all day and all night, prophesying in the presence of Samuel. The people who were watching exclaimed, "What? Is even Saul a prophet?"
Matthew Henry's Commentary on 1 Samuel 19:20-24
Commentary on 1 Samuel 19:11-24
(Read 1 Samuel 19:11-24)
Michal's stratagem to gain time till David got to a distance was allowable, but her falsehood had not even the plea of necessity to excuse it, and manifests that she was not influenced by the same spirit of piety which had dictated Jonathan's language to Saul. In flying to Samuel, David made God his refuge. Samuel, as a prophet, was best able to advise him what to do in this day of distress. He met with little rest or satisfaction in Saul's court, therefore went to seek it in Samuel's church. What little pleasure is to be had in this world, those have who live a life of communion with God; to that David returned in the time of trouble. So impatient was Saul after David's blood, so restless against him, that although baffled by one providence after another, he could not see that David was under the special protection of God. And when God will take this way to protect David, even Saul prophesies. Many have great gifts, yet no grace; they may prophesy in Christ's name, yet are disowned by him. Let us daily seek for renewing grace, which shall be in us as a well of water springing up into everlasting life. Let us cleave to truth and holiness with full purpose of heart. In every danger and trouble, let us seek protection, comfort, and direction in God's ordinances.