What event is cited in Chapter 40 as the inspiration for the Shri Sai Satcharitra, and what divine principle does this relate to?

According to Chapter 40, the root inspiration for the Shri Sai Satcharitra was the sight of Sai Baba, a great saint, grinding grain. The author recalls this image, noting how Baba would set up the grinding stone and pour the grain, and this sight filled his mind with wonder. This led to a "strong desire" to describe all of Sai's deeds, with the faith that doing so would destroy impurities and sins. This act of praise relates to a key divine principle mentioned in the chapter: God (Hari) is immensely pleased, even more than by His own praise, when someone sings the praises and describes the qualities of His devotees. Chapter 40 even notes that this statement is substantiated in the Bhavishyottara Purana, as declared by Tripurari (Shiva).