1 Samuel 23:17-21

He said to him, “Do not be afraid, because the hand of Saul my father will not find you, and you will be king over Israel, and I will be second in command to you; and Saul my father knows that as well.”

So the two of them made a covenant before the Lord; and David stayed at Horesh, while Jonathan went to his house.

Then Ziphites came up to Saul at Gibeah, saying, “Is David not keeping himself hidden with us in the strongholds at Horesh, on the hill of Hachilah, which is south of Jeshimon?

Now then, O king, come down, since you fully desire to do so; and our part shall be to hand him over to the king.”

Saul said, “May you be blessed of the Lord, since you have had compassion on me.