Why did Sai Baba continuously purchase firewood and maintain a perpetual fire in the Dwarkamai?

Chapter 33 of the Shri Sai Satcharita explains that Sai Baba's practice of purchasing firewood and maintaining the perpetual Dhuni was central to his teachings. He would buy bundles of logs and offer them into the sacred fire in front of him. The primary purpose of this constant fire was to produce Udi, the sacred ash. This Udi was then used in his daily interactions, given to devotees as a blessing and as a sign of permission to leave Shirdi. As Chapter 33 further elaborates, the perpetually burning fire and the resulting ash served as a constant, tangible lesson on the impermanent nature of the universe and the physical body.