According to Chapter 51, what specific narrative about Kakasaheb will be told, and why is it important?

Chapter 51 explicitly sets the stage for a detailed account of Kakasaheb's connection to Shirdi. The text promises to narrate "the marvelous account of how Kakasaheb was established in Shirdi." The importance of this story, as highlighted in Chapter 51, is that it will reveal the history of his "bond of past lives (rinanubandh) with Shirdi and his firm relationship with Sai." While many of Kakasaheb's stories were already known, this particular origin story was not. The chapter suggests that this narrative demonstrates how the grace of the Supreme Lord and the merits of past lives lead a disciple to their Sadguru, strengthening their spiritual bliss.