And the LORD sent Nathan unto David. And he came unto him, and said unto him, There were two men in one city; the one rich, and the other poor. There were two men in one city - See a discourse on fables at the end of Judges 9:56 (note), and a discourse on parabolic writing at the end of the thirteenth chapter of Matthew.
There is nothing in this parable that requires illustration; its bent is evident; and it was construed to make David, unwittingly, pass sentence on himself. It was in David's hand, what his own letters were in the hands of the brave but unfortunate Uriah.