Based on Chapter 33, why did Sai Baba maintain a constantly burning fire, or Dhuni, in the mosque?

Chapter 33 explains that the Dhuni, the perpetually burning sacred fire, was central to Sai Baba's daily activities and teachings. Its primary function was to produce the sacred ash, or Udi. The text describes how Baba would feed the fire with logs of wood, and the resulting ash was collected and distributed. The deeper reason for the Dhuni was symbolic, as it perfectly demonstrated his teaching on impermanence. The fire transforming wood into ash was a living metaphor for the transient nature of the material world and the human body. Therefore, the Dhuni was not just a fire; it was the very source of the Udi that Baba used to impart his most profound spiritual lessons.