The king of Babylon is any power in the world of form that seems large enough to destroy you. The mind magnifies it, rehearses the harm it might do, and calls this fear wisdom. So you are defeated already, by something that has not even happened.
Be not afraid of him. The presence that says I am with you does not promise that no difficulty will come. It reminds you that beneath every outer threat is an awareness in you that cannot be harmed. When you rest there, the king loses his grip, because the fear he ruled you with lived in your mind, not in his hand.