Charles Ellicott Commentary 1 Samuel 11:6

"And the Spirit of God came mightily upon Saul when he heard those words, and his anger was kindled greatly." — 1 Samuel 11:6 (ASV)

And the Spirit of God came upon Saul. —Nothing, perhaps, could have moved Saul so deeply as this news concerning the distress of Jabesh-gilead; he was affected not merely by the disgrace to Israel, over which the Eternal had just recently directed him to be anointed king, but by the grave danger that threatened the ancient friend and ally of his tribe. On Saul’s heart, thus prepared for action, the Holy Spirit fell, and endowed him with extraordinary wisdom, valor, and power for the great and difficult work that lay before him.

We read of the Spirit of the Lord coming upon men like Othniel (Judges 3:10) and the other great Israelite judges, who were raised up to be in their day the deliverers of the people. The immediate result of the Spirit of the Lord coming upon them was to impart new and unusual power to their spirit, power that enabled them successfully to surmount every danger and difficulty that barred the progress of the great work they were specially called upon to do.