1 Samuel 20:11-17

Then Jonathan said, “Come, let’s go out into the field.” So the two of them went out into the field. Jonathan said to David, “I promise this before the LORD, the God of Israel: At this same time the day after tomorrow, I will find out how my father feels. If he feels good toward you, I will send word to you and let you know. But if my father plans to hurt you, I will let you know and send you away safely. May the LORD punish me terribly if I don’t do this. And may the LORD be with you as he has been with my father. But show me the kindness of the LORD as long as I live so that I may not die. You must never stop showing your kindness to my family, even when the LORD has destroyed all your enemies from the earth.” So Jonathan made an agreement with David. He said, “May the LORD hold David’s enemies responsible.” And Jonathan asked David to repeat his promise of love for him, because he loved David as much as he loved himself.