What is the significance of Udi as discussed in the Shri Sai Satcharitra?

The Shri Sai Satcharitra describes Udi, the sacred ash from Sai Baba's fire, as having immense healing power and spiritual significance. Chapter 34 introduces the 'Glory of Udi,' stating that it continues the narration from the previous chapter about its wonderful qualities. The text provides a powerful example, mentioning how a terrible disease like a bone-cyst (Hadyavran), which was incurable by any other remedy, could be completely healed by smearing it with Udi from Sai's hand. This illustrates that Udi is not merely ash, but a medium of Sai's grace and protection, capable of uprooting deep-seated pain and suffering for those with faith.