1 Samuel 19:4-6

The next morning Jonathan spoke with his father about David, saying many good things about him. “The king must not sin against his servant David,” Jonathan said. “He’s never done anything to harm you. He has always helped you in any way he could. Have you forgotten about the time he risked his life to kill the Philistine giant and how the LORD brought a great victory to all Israel as a result? You were certainly happy about it then. Why should you murder an innocent man like David? There is no reason for it at all!” So Saul listened to Jonathan and vowed, “As surely as the LORD lives, David will not be killed.”