What is Udi and where did Sai Baba get it from?

Udi is sacred ash that Sai Baba would distribute to his devotees. As explained in Chapter 33, this Udi came from the daily Dhuni, which was a fire that burned constantly, day and night, in the Masjid. Baba would take handfuls of the ash from this fire and give it as a benediction, or Prasad. The text clarifies that the words Ash, Vibhuti, and Udi all refer to the same substance. He would apply it to devotees' foreheads and place his hand on their heads, wishing for their welfare, making it a central part of his blessings.