1 Kings 20:11-17

And Jonathan said to David: Come and let us go out into the field. And when they were both of them gone out into the field, Jonathan said to David: O Lord God of Israel, if I shall discover my father's mind, to-morrow or the day after, and there be any thing good for David, and I send not immediately to thee, and make it known to thee, May the Lord do so and so to Jonathan, and add still more. But if my father shall continue in malice against thee, I will discover it to thy ear; and will send thee away, that thou mayest go in peace, and the Lord be with thee, as he hath been with my father. And if I live, thou shalt shew me the kindness of the Lord: but if I die, Thou shalt not take away thy kindness from my house for ever, when the Lord shall have rooted out the enemies of David, every one of them from the earth. May he take away Jonathan from his house: and may the Lord require it at the hands of David's enemies. Jonathan therefore made a covenant with the house of David: and the Lord required it at the hands of David's enemies. And Jonathan swore again to David, because he loved him: for he loved him as his own soul.