1 Samuel 16:15

15. An evil spirit… troubleth thee A demon like those mentioned so frequently in the New Testament, sent by permission of the Lord, as Satan in the case of Job. Job 2:7. See notes on Matthew 4:24, and Mark 5:2. It is not only by Saul’s servants, but by the sacred writer himself, that we are told it was an evil spirit from the Lord; so we cannot regard it as merely a superstitious and mistaken notion of Saul’s physicians. Compare 1 Samuel 18:10; 1 Samuel 19:9. But while he thus became possessed by a supernatural evil power, it is very likely that a mental disease bordering on insanity was the substratum on which the evil spirit worked. After Samuel’s last words of judgment the king could not be happy in his kingdom. The more he thought upon his doom, the more it harrowed up his soul. It was, perhaps, his highest ambition to be the father of a race of kings, and to have this hope suddenly dashed from him was to have darkness settle over all his life. “The Hebrew mind so linked itself to the future by the contemplation of posterity that it is scarcely possible to us, with our looser attachment to the time beyond ourselves, to apprehend, in all its intensity, the deep distress of mind with which any Hebrew, and much more a king, regarded the prospect that there would be no son of his succeeding.” Kitto. Saul’s future gradually became full of ghostly images, and when, disengaged at times from the excitements of war and the cares of government, he sat down to think upon his darkened fortunes, his mind and heart, forsaken of all divine influences from Jehovah, became an easy prey to foul suspicions and gloomy fears a most inviting state for demoniacal possession. The evil spirit, entering and revelling amid these mental disorders, carried him at times to the wildest height of madness.