Can you summarize the main teachings about the glory of Udi from Chapter 33 of the Shri Sai Satcharita?

Chapter 33 of the Shri Sai Satcharita is dedicated to explaining the glory and importance of Udi in Sai Baba's teachings. It describes both the practical and philosophical aspects of this sacred ash. Practically, Baba maintained a perpetual Dhuni (sacred fire), fed it with firewood, and distributed the resulting Udi to all devotees, especially as a sign of permission for those leaving Shirdi. Philosophically, as this chapter clarifies, the Udi was a powerful symbol. Baba used it to teach the profound lesson of impermanence, reminding everyone that the physical body and the entire visible universe are transient and will ultimately turn to ash. The Udi served as a constant reminder to distinguish the real (Brahman) from the illusory (Maya).