Can you tell me the story of Das Ganu's pilgrimage to Prayag as described in Chapter 22?

Chapter 22 recounts the story of Das Ganu, who sought permission from Sai Baba to go bathe in the holy waters of Prayag. In response, Baba instructed him, "Know this big toe of Mine to be Prayag; bathe right here." When Das Ganu followed this command and placed his head on Baba's feet, a miracle occurred. As described in the chapter, the sacred waters of both the Ganga and Yamuna rivers manifested right there from Baba's big toe, satisfying Das Ganu's desire for a holy bath, thereby proving the immense power and sanctity of the Sadguru's feet.