Can you explain the philosophical idea of Sai moving from 'Nirgun' to 'Sagun' as mentioned in Chapter 30?

In Chapter 30, a profound philosophical concept is presented regarding Sai Baba's nature. The chapter begins by stating that in the beginning, Sai resides as the formless, or 'Nirguni.' This refers to the ultimate, attributeless, and unmanifested divine reality. However, the text explains that through the power and qualities of his devotees' devotion, this formless essence is drawn into a form with attributes, becoming 'Saguni.' This transition signifies that the abstract, transcendent divine takes on a perceivable, personal form to interact with and guide devotees. It underscores the immense power of bhakti (devotion) in making the divine accessible to human experience, as seen in the person of Sai Nath, the crest-jewel among saints.