What specific event or image inspired the author to begin writing the Shri Sai Satcharitra, as mentioned in Chapter 40?

Chapter 40 reveals the specific inspiration behind the creation of the Shri Sai Satcharitra. The author recalls the image of Sai Baba in Shirdi, sitting with his legs spread, grinding grain. The text describes this act of a saint grinding grain as filling the author's mind with wonder. This powerful image sparked a "strong desire" in the author's mind to describe all of Sai's deeds, believing that by doing so, his own impurities and sins would be destroyed. This chapter also notes that God Himself is pleased when the praises of His devotees are sung.