Chapter 40 uses several analogies to illustrate spiritual concepts. What are they, and what do they teach?

Chapter 40 employs several powerful analogies to illustrate spiritual concepts. It uses the metaphor of a river meeting the ocean to describe how a devotee who seeks exclusive refuge in the Sadguru merges with Him, losing all sense of difference. The chapter also describes Sai's act of grinding grain as the root inspiration for the book, a deed that sparked the author's desire to destroy sins by narrating Sai's glory. Finally, as Chapter 40 explains, the author Hemadpant uses the analogy of a puppet and puppeteer to define his role, stating he is a mere instrument whose strings are pulled by Sai, the true author of the work.