What is the primary purpose and content introduced in Chapter 51 of the Sai Satcharitra?

Chapter 51 of the Shri Sai Satcharitra serves as an introduction to several key themes and stories. It begins with invocations and emphasizes the purifying power of listening to the Sai Charitra, stating that both the listener and speaker become sanctified. The chapter references the previous one's discussion on destroying ignorance, drawing parallels to the Bhagavad Gita where Arjuna tells Krishna his delusion has vanished. It then sets the stage for the stories to follow, promising to narrate the marvelous account of how Kakasaheb was established in Shirdi and the history of his bond with Sai. As mentioned in Chapter 51, it will also describe three other stories of devotees, which are intended to soothe the hearts of the listeners.