But the king spared Mephibosheth, the son of Jonathan the son of Saul, because of the LORD's oath that was between them, between David and Jonathan the son of Saul.

David said, "Is there yet any who is left of the house of Saul, that I may show him kindness for Jonathan's sake?" There was of the house of Saul a servant whose name was Ziba, and they called him to David; and the king said to him, "Are you Ziba?" He said, "Your servant is he." The king said, "Is there not yet any of the house of Saul, that I may show the kindness of God to him?" Ziba said to the king, "Jonathan has yet a son, who is lame of his feet." read more.
The king said to him, "Where is he?" Ziba said to the king, "Behold, he is in the house of Machir the son of Ammiel, in Lo Debar." Then king David sent, and fetched him out of the house of Machir the son of Ammiel, from Lo Debar. Mephibosheth, the son of Jonathan, the son of Saul, came to David, and fell on his face, and showed respect. David said, "Mephibosheth." He answered, "Behold, your servant." David said to him, "Do not be afraid of him; for I will surely show you kindness for Jonathan your father's sake, and will restore to you all the land of Saul your father. You shall eat bread at my table continually."