I Samuel 23:15-18

So David saw that Saul had come out to seek his life. And David was in the Wilderness of Ziph in a forest. Then Jonathan, Saul’s son, arose and went to David in the woods and strengthened his hand in God. And he said to him, “Do not fear, for the hand of Saul my father shall not find you. You shall be king over Israel, and I shall be next to you. Even my father Saul knows that.” So the two of them made a covenant before the LORD. And David stayed in the woods, and Jonathan went to his own house.