What is the primary significance of the Udi (sacred ash) that Sai Baba distributed, as explained in Chapter 33?

According to Chapter 33 of the Shri Sai Satcharitra, the Udi distributed by Sai Baba carried a profound philosophical significance. Baba used the ash to teach about the transient nature of the physical world. The chapter explains that Baba wished to convey that the entire visible universe is illusory (Maya) and ultimately impermanent, just like ash. He taught that the human body, made of five elements, will also turn to ash once its destined experiences are over. Therefore, as detailed in this chapter, the Udi served as a constant, tangible reminder to cultivate detachment and to remember that only Brahman is the ultimate, eternal reality.