Can you describe the specific circumstances that led to Sai Baba initiating a discussion about the Bhagavad Gita with Nana Chandorkar?

The event is detailed in Chapter 39, which recounts a moment when the great devotee Nana Chandorkar was serving Sai Baba in the Masjid. While massaging Baba's feet, Chandorkar was quietly humming the fourth chapter of the Bhagavad Gita. As he was reciting, Sai Baba, who possesses knowledge of the past, present, and future, felt a desire to explain the deeper meaning of the scripture to Nana. Baba interrupted the faint humming and asked Nana to speak the verse clearly so He could hear it. This question paused the recitation and set the stage for the 'Sai-Nana dialogue,' a profound teaching moment initiated by the Guru.