1 Samuel 20:12-15

And Jonathan said to David, “The LORD, the God of Israel, be witness! When I have sounded out my father, about this time tomorrow, or the third day, behold, if he is well disposed toward David, shall I not then send and disclose it to you? But should it please my father to do you harm, the LORD do so to Jonathan and more also if I do not disclose it to you and send you away, that you may go in safety. May the LORD be with you, as he has been with my father. If I am still alive, show me the steadfast love of the LORD, that I may not die; and do not cut off your steadfast love from my house forever, when the LORD cuts off every one of the enemies of David from the face of the earth.”