1 Samuel 20:11-17

And Jonathan said unto David, Come, and let us go out into the field. And they went out both of them into the field. And Jonathan said unto David, Jehovah, the God of Israel, be witness: when I have sounded my father about this time to-morrow, or the third day, behold, if there be good toward David, shall I not then send unto thee, and disclose it unto thee? Jehovah do so to Jonathan, and more also, should it please my father to do thee evil, if I disclose it not unto thee, and send thee away, that thou mayest go in peace: and Jehovah be with thee, as he hath been with my father. And thou shalt not only while yet I live show me the lovingkindness of Jehovah, that I die not; but also thou shalt not cut off thy kindness from my house for ever; no, not when Jehovah hath cut off the enemies of David every one from the face of the earth. So Jonathan made a covenant with the house of David, saying, And Jehovah will require it at the hand of David’s enemies. And Jonathan caused David to swear again, for the love that he had to him; for he loved him as he loved his own soul.