Once David had some security in his kingship, he seeks out Jonathan’s kin and discovers that Jonathan’s crippled son Mephibosheth is still alive (and has a son of his own) and has survived the political assassinations and turmoil that were part of the aftermath of Saul’s death.
Chiastic literary structures you find in the TaNaK (Torah, Prophets and Writings) and the Apostolic Scriptures give us prophetic clues in texts that don’t seem to be prophetic at all.