What was the specific problem Das Ganu faced while writing his commentary on the Ishavasya Upanishad, and what strange advice did Sai Baba give him?

In Chapter 20, we learn that Das Ganu was writing a commentary called 'Ishavasya-Bhavartha-Bodhini' to explain the Ishavasya Upanishad in simple Prakrit language for people unfamiliar with Sanskrit. Although he managed a word-for-word translation, he felt his work lacked depth because he couldn't grasp the 'internal secret' or deep meaning of the scripture, which brought him no joy. When he took this doubt to Sai Baba in Shirdi, Baba gave him the perplexing instruction that the resolution to his problem would come from the maidservant at Kaka's house upon his return.