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

When Das Ganu approached Sai Baba in Shirdi with his doubt about the deep meaning of the Ishavasya Upanishad, Baba's response was quite unexpected. As recorded in Chapter 20, instead of providing a direct scriptural explanation, Sai 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 instruction was unusual because it pointed Das Ganu towards a seemingly ordinary and unscholarly source—a maidservant—to find the profound spiritual clarity he was seeking for his commentary.