Can you recount the story from Chapter 22 about Das Ganu and the holy rivers at Prayag?

Certainly. Chapter 22 of the Shri Sai Satcharitra details a memorable incident involving Das Ganu. When Das Ganu sought permission to travel to Prayag to bathe in the holy waters, Sai Baba offered a profound teaching. He told Das Ganu, "Know this big toe of Mine to be Prayag; bathe right here." The chapter narrates that as soon as Das Ganu placed his head on Baba's feet in acceptance, the sacred waters of both the Ganga and Yamuna rivers miraculously flowed from that very spot. This event satisfied Das Ganu's desire and demonstrated that the Guru's feet are the ultimate place of pilgrimage.