What was the specific problem Das Ganu was having with his work on the Ishavasya Upanishad, and what was Baba's strange advice to him?

As detailed in Chapter 20, Das Ganu was composing the "Ishavasya-Bhavartha-Bodhini," a commentary on the Upanishad. His problem was that although he could translate the text word for word into simple Prakrit language, he felt he was missing the profound "internal secret" and deep meaning. This lack of true understanding meant his mind found no joy in the work. When he brought this doubt to Sai Baba in Shirdi, Baba gave him the cryptic advice that the resolution to his doubt would come from the maidservant at Kaka's house upon his return.