Who is The Old King from A Tale of Three Kings and what is their importance?

The Old King is a man who comes to visit David at his home. The Old King takes a look at David and decides that he is destined to become a great king. The Old King tells David and his family that he has a great future and he should prepare for it properly. David is surprised by this prophecy because he is the youngest son of a shepherd, not really the kind of person who is destined to be a great king. However, David and his family take the King's words to heart and begin to prepare David for his future. David will do great things in his life, but most of them he will do because he makes himself open to God, not because he wants to do what he can to fulfill the King's prophecy.