1 Samuel 20:3

20:3 Taking an oath, David again said, “Your father is very much aware of the fact that I have found favor with you, and he has thought, ‘Don’t let Jonathan know about this, or he will be upset.’ But as surely as the Lord lives and you live, there is about one step between me and death!”

1 Samuel 20:16-17

20:16 and called David’s enemies to account.” So Jonathan made a covenant with the house of David. 20:17 Jonathan once again took an oath with David, because he loved him. In fact Jonathan loved him as much as he did his own life.