1 Samuel 20:17 (KJV)

But also thou shalt not cut off thy kindness from my house for ever: no, not when the Lord 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, Let the Lord even require it at the hand of David’s enemies.

And Jonathan caused David to swear again, because he loved him: for he loved him as he loved his own soul.

Then Jonathan said to David, To morrow is the new moon: and thou shalt be missed, because thy seat will be empty.

And when thou hast stayed three days, then thou shalt go down quickly, and come to the place where thou didst hide thyself when the business was in hand, and shalt remain by the stone Ezel.