What is the central theme of Chapter 34, and what specific story is used to illustrate it?

Chapter 34 of the Shri Sai Satcharitra continues the narration on the glory and power of Udi. The chapter uses a specific story to illustrate this theme, involving a doctor from Malegaon whose nephew was afflicted with a terrible bone-cyst, also known as Hadyavran. Despite trying all native and foreign medical treatments, including surgery, the ailment persisted, causing immense suffering. As detailed in this chapter, the family eventually sought the help of Sai Baba as a last resort, leading to a demonstration of the Udi's miraculous healing properties when Baba instructed them to apply it to the wound.