How did Sai Baba engage with Nana Chandorkar to teach him about a specific verse from the Gita?

Based on the narrative in Chapter 39, Sai Baba initiated a profound teaching moment with Nana Chandorkar by first noticing him humming a verse. Baba then commanded Nana to recite the verse clearly and provide a detailed explanation of its meaning. This interaction, described as the "Sai-Nana dialogue," was Baba's unique method to impress the true teaching upon his devotee. Nana, in his humility, complied and prepared to explain the verse from the Gita, showcasing the dynamic of their Guru-disciple relationship as a means of imparting wisdom.