Can you explain the story of Das Ganu's doubt regarding the Ishavasya Upanishad and how Sai Baba proposed to resolve it?

The story of Das Ganu's doubt is a central theme in Chapter 20. After creating a verse-commentary on the Ishavasya Upanishad, a specific doubt arose in his mind that even learned scholars could not resolve to his satisfaction. He then traveled to Shirdi and presented his issue to Sai Baba. Instead of providing a direct answer, Baba told him something quite unusual: "The resolution of this doubt of yours will be done by the maidservant at Kaka’s house when you return there." This demonstrates Sai Baba's unique method of providing solutions and guidance, showing that knowledge can come from unexpected sources when the Guru's grace is present.