What are the main narratives and teachings presented in the 20th chapter of Sai Satcharitra?

Chapter 20 of the Sai Satcharitra begins with invocations and a description of Sai Baba's divine nature, explaining that while he is formless, he took a physical body for his devotees. The chapter vividly portrays the scene at the Shirdi Masjid after the noon Aarti, detailing how Baba lovingly distributed Udi to everyone. It then transitions to the main story concerning Das Ganu, who was writing a commentary on the Ishavasya Upanishad but became stuck, unable to grasp its deeper meaning. Upon seeking Baba's help, he is mysteriously told that a maidservant will resolve his doubt. The chapter uses this story to emphasize a key teaching: the absolute necessity of a Guru's grace to understand profound spiritual truths, stating that scholarly effort alone is insufficient.