1 Samuel 20:12-16

Then Jonathan said to David, “The Lord, the God of Israel, is my witness! When I have sounded out my father about this time tomorrow or the third day, behold, if he has a good feeling toward you, shall I not then send word to you and inform you?

If it pleases my father to do you harm, may the Lord do so to me and more so, if I fail to inform you and send you away, so that you may go in safety. And may the Lord be with you as He has been with my father.

And if I am still alive, will you not show me the faithfulness of the Lord, so that I do not die?

And you shall never cut off your loyalty to my house, not even when the Lord cuts off every one of the enemies of David from the face of the earth.”

So Jonathan made a covenant with the house of David, saying, “May the Lord demand it from the hands of David’s enemies.”