What was Sai Baba's peculiar instruction to Das Ganu about resolving his doubt?

When Das Ganu approached Sai Baba in Shirdi with a profound doubt about the meaning of the Ishavasya Upanishad, Baba did not provide a direct explanation. Instead, as narrated in Chapter 20, he gave a very peculiar instruction. Baba told Das Ganu, "The resolution of this doubt of yours will be done by the maidservant at Kaka’s house when you return there." This surprising prophecy, delegating the clarification of complex scripture to a seemingly ordinary maidservant, sets up the main story that the chapter intends to unfold.