I'm trying to understand the part in Chapter 30 about 'Nirguni' and 'Saguni'. Can you explain what that means in the context of Sai?

Chapter 30 of the Sri Sai Satcharita touches upon the philosophical concept of Sai's transition from 'Nirguni' (formless) to 'Saguni' (with form). The text explains that in the beginning, Sai resides as the formless, absolute reality. However, it is 'through the qualities of devotees' devotion' that He is drawn from this formless state into a form with attributes. As Chapter 30 states, this makes Him the 'crest-jewel among saints.' This concept implies that Sai Baba's physical manifestation was a direct response to the love and yearning of His followers, making the abstract divine accessible and relatable to them.