Can you tell me the story about Das Ganu wanting to visit Prayag as recounted in Chapter 22?

Chapter 22 narrates a wonderful incident involving Das Ganu. When Das Ganu sought permission from Sai Baba to go bathe in the holy waters at Prayag, Baba instructed him differently. Baba told him, "Know this big toe of Mine to be Prayag; bathe right here." Trusting his Guru, when Das Ganu placed his head on Baba's feet, a miracle occurred. As described in Chapter 22, the holy 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.