Can you summarize the key themes and stories presented in Chapter 22 of the Shri Sai Satcharitra?

Chapter 22 of the Shri Sai Satcharitra covers several key themes, beginning with a philosophical invocation. It describes the Sadguru as the destroyer of worldly fear, using an analogy where the Guru is the light that reveals an illusory snake to be a simple rope. The chapter then describes the bliss devotees experience at Baba's feet, linking the longing for a vision to the way one might search for the new moon. This leads to a specific description of how devotees could see a moon-like nail on Baba's toe. Finally, as Chapter 22 concludes, it narrates the powerful story of Das Ganu, for whom Baba manifests the holy Ganga and Yamuna rivers from His big toe, equating His feet with the holy site of Prayag.