According to the introduction in Chapter 51, what specific story about Kakasaheb will be told, and why is it considered noteworthy?

According to Chapter 51, the narrative that will be shared is the history of how Kakasaheb first came to Shirdi and became established there. The chapter highlights that this particular story is noteworthy because, while many of Kakasaheb's stories were widely known among devotees, the circumstances of his initial arrival in Shirdi were not. As mentioned in Chapter 51, this account will delve into his "bond of past lives (rinanubandh) with Shirdi" and his firm relationship with Sai, illustrating how the grace of the Supreme Lord leads a disciple to their Sadguru.