Chapter 40 mentions a specific act of Sai Baba that served as a primary inspiration for the book. What was this act and what larger spiritual principle does it connect to?

Chapter 40 reveals that the root inspiration for the Shri Sai Satcharitra was the author witnessing Sai Baba's act of setting up a grinding stone and grinding grain in Shirdi. This sight filled the author's mind with wonder and sparked a strong desire to describe Sai's deeds. This connects to a larger principle also mentioned in this chapter: God (Hari) is deeply pleased, even more than by praises to Himself, when someone sings the praises and describes the qualities of His devotees. This truth, the text notes, is supported by the Bhavishyottara Purana.