What was Baba's surprising instruction to Das Ganu regarding his doubt about the Upanishad?

When Das Ganu arrived in Shirdi and presented his doubt about the Ishavasya Upanishad, Sai Baba's response was unexpected. Instead of providing a direct explanation of the scripture, Baba gave him a peculiar instruction. As recorded in Chapter 20, Baba told him, 'The resolution of this doubt of yours will be done by the maidservant at Kaka’s house When you return there.' This pointed Das Ganu towards an unconventional source for spiritual clarification, setting up the subsequent events of the story.