2 Samuel 9:1

“You shall not cut off your lovingkindness from my house forever, not even when Yahweh cuts off every one of the enemies of David from the face of the earth.”

So the two of them cut a covenant before Yahweh; and David stayed at Horesh while Jonathan went to his house.

And David said to him, “Do not fear, for I will surely show lovingkindness to you for the sake of your father Jonathan, and will restore to you all the land of your grandfather Saul; and you shall eat at my table continually.”

But the king spared Mephibosheth, the son of Jonathan the son of Saul, because of the oath of Yahweh which was between them, between David and Saul’s son Jonathan.

David’s Lovingkindness to Mephibosheth