How did Sai Baba initiate a discussion about the Bhagavad Gita with Nana Chandorkar?

The discussion began while the great devotee Nana Chandorkar was massaging Sai Baba's feet in the Masjid. As described in Chapter 39, Nana was humming the fourth chapter of the Bhagavad Gita. Sai, who knows the past, present, and future, felt a desire to explain the Gita's meaning to him. Baba intentionally paused Nana's recitation at the 34th verse and asked him what he was muttering, requesting him to speak the verse clearly so it could be heard. This question became the starting point for a profound dialogue.