1 Samuel 19:6-9

Saul sware, As the Lord liveth And, without all doubt, he intended what he said, feeling a real change in himself for the present. “God,” says Mr. Henry, “inclined the heart of Saul to hearken to the voice of Jonathan.” From this, however, and other similar instances, it appears that Saul was of a hasty, precipitate temper; and that he had too little reverence for an oath. And as he swore inconsiderately, so, he as quickly and inconsiderately broke his oath; which may be a lesson to us never to take an oath upon any occasion, but with the greatest seriousness and an inward veneration, 1 Samuel 19:8. And there was war again The battles of which were only between parties, for David commanded no more than a thousand men, 1 Samuel 18:13. And if the whole army of the Philistines had been gathered together, Abner would have commanded the army of Israel against them; for he was captain of the host. David went out and fought with the Philistines So David continues his good services, though they were ill requited. They who are ill paid for doing good, yet must not be weary of well-doing, remembering how bountiful a benefactor God is, even to the evil and unthankful. The evil spirit was upon Saul David's successes against the Philistines revived his envy, and the devil watched the opportunity as he had done before. And David played with his hand He did not omit his duty to Saul, though he knew his danger.