Next to the king himself, Mordecai was the highest official in the kingdom. He was a popular leader of the Jews, because he helped them in many ways and would even speak to the king for them.
The chief priests and the teachers of the Law of Moses knew that Jesus was talking about them when he was telling this story. They wanted to arrest him at once, but they were afraid of the people.
David was a success in everything that Saul sent him to do, and Saul made him a high officer in his army. That pleased everyone, including Saul's other officers.