Saul now abandoned pretense (18:22) and ordered Jonathan and his servants to put David to death (cf. v. 11). He "went public"with his attacks against David feeling driven, like Pharaoh, to more desperate measures. This created a conflict of loyalties for Jonathan who needed to honor his father and king, but who also loved David (cf. 19:1, 3). Jonathan chose to tell David what Saul's intentions were, but he also tried to honor his father by urging him not to kill David. He appealed to Saul logically and rationally. He reminded Saul that he was the king and that David was his servant, that he needed to be fair with David, and that it was in Saul's best interest to let David live (v. 4). He also reminded Saul that David was the Lord's instrument who had defeated Israel's enemies and that Saul had rejoiced in his success. Moreover he appealed for justice since David's death was unwarranted (v. 5). Jonathan's words echo Saul's own statement when he had freed Jabesh-gilead earlier in his reign (11:12-15). Then Saul had generously refused to punish his detractors. Perhaps it was this memory that moved him to promise Jonathan that he would be merciful to David.
Jonathan's appeal was successful, at least temporarily, and resulted in Saul solemnly vowing not to kill David (v. 6), which vow he broke shortly (v. 10). Later Jonathan was not as successful (20:28-29). Nevertheless this time his appeal resulted in David's restoration to the court and his continuing ministry to the king (v. 7).
