Can you explain how Sai is described in relation to the Supreme Divinity in Chapter 4?

In Chapter 4, Sai is equated with the Supreme Divinity, the Inner Self who brings joy to the world. The text posits that God, the Guru, and the Joy-giving Shankar are all one and the same. This Supreme Being is described as the object of ultimate love, eternal, and non-dual, existing beyond the limitations of place, time, or object. The chapter emphasizes the ineffable nature of this divinity, stating that even the four levels of speech and the Vedas, which resorted to saying 'Not this, Not this' (Neti-Neti), fail to fully describe Him.