What problem did Das Ganu have with the Ishavasya Upanishad, and what strange advice did Sai Baba give him?

According to Chapter 20, Das Ganu was composing a commentary called the 'Ishavasya-Bhavartha-Bodhini' to explain the Upanishad in simple language. However, he became stuck because he couldn't grasp the deep, internal meaning, and his mind found no joy in a simple word-for-word translation. When he took this doubt to Sai Baba in Shirdi, Baba gave him the unusual instruction that the doubt would be resolved by the maidservant at Kaka's house when he returned there. This connection is set up at the end of the chapter to be continued later.