What is the full story about Nana Chandorkar's recitation of the Bhagavad Gita that is told in Chapter 50?

Chapter 50 does not contain the full story about Nana Chandorkar and the Bhagavad Gita. It only makes a brief, passing reference to a past event. The text notes, "previously in this Satcharitra, in the thirty-ninth chapter, The Samarth (Sai) gave an instruction to a most excellent devotee" who was reciting the fourth chapter of the Gita. The actual focus of Chapter 50 is on the nature of non-dual devotion and the proper mindset for reading the Satcharitra, urging the listener to see the reader, the reading, and Sai as one unified state, and to recognize that Sai alone is the one who "makes the words speak."