How does the author describe the qualities of an effective and captivating narration at the beginning of Chapter 21?

At the start of Chapter 21, the author reflects on what makes a narration truly impactful. He suggests that the speaker's words are in vain if they don't produce a profound physical and emotional reaction in the listener. According to the text, a successful narration is one where the listener sways upon hearing the stories, the hair on their body stands on end, their throat chokes up with emotion, and tears of love and joy flow from their eyes. The chapter posits that any narration that fails to delight the listeners and evoke such a deep response is considered futile.