According to Chapter 28, what is the nature of Sai and how is a Sadguru defined?

Chapter 28 explains that Sai is omnipresent and not separate from anyone, dwelling within all beings, from the highest deity Brahma down to the smallest insect. The text states that a Sadguru possesses a dual proficiency, being complete in both Shabda-Brahma (the divine word) and showing signs of Para-Brahman (the Supreme Being). Furthermore, this chapter highlights the profound compassion of a Guru, who can remove the cycles of both birth and death for a disciple, which is a mercy that surpasses even that of a father who only gives birth to the physical body.