What does the author say about the qualities of a good story or narration at the beginning of Chapter 21?

At the start of Chapter 21, the author reflects on what makes a narration powerful and effective. He suggests that a speaker's words are wasted if the listener does not "sway upon hearing them" or feel their hair stand on end. He considers narrations futile if they fail to delight the audience, cause their throat to choke up with emotion, and bring tears of love and joy to their eyes. This commentary sets a high standard for the spiritual stories that follow, emphasizing their purpose is to evoke a deep emotional and spiritual response in the reader.