What are the main themes and stories presented in Chapter 20 of the Sai Satcharitra?

Chapter 20 of the Sai Satcharitra presents several key themes and stories. It begins by describing the scene at Shirdi after the noon Aarti, where Sai Baba lovingly distributes Udi to his devotees, applying it to their foreheads and sending them to eat. As narrated in Chapter 20, this act is filled with boundless love. The chapter then transitions to the story of Das Ganu, who was writing a commentary on the Ishavasya Upanishad but struggled to understand its deeper meaning. This story serves to illustrate a major theme of the chapter: the absolute necessity of a Guru's grace to understand profound spiritual knowledge, as self-effort alone is insufficient to grasp hidden truths.