Charles Ellicott Commentary 1 Samuel 19:4

"And Jonathan spake good of David unto Saul his father, and said unto him, Let not the king sin against his servant, against David; because he hath not sinned against thee, and because his works have been to thee-ward very good:" — 1 Samuel 19:4 (ASV)

Jonathan spoke well of David. —The heir to the throne—the one above all men most likely to be harmed by David's growing popularity—with great power and intense earnestness, described to his father the king the great virtues, the unrivalled gifts, and, above all, the splendid services of the young soldier whose life Saul was so eager to cut short. “See,” urged the eloquent pleader for his friend’s life, “on that ever-memorable occasion when he fought the giant, when he aimed the pebble of the brook from his shepherd’s sling, he put his life in his hand. Had he missed by a hair’s breadth, the giant would have slain him, and the deliverance then brought about for Israel would never have been accomplished.”