Baba declared that He is the goal of all Yagna (Sacrifice, renunciation) So too, He is the entity, known by the Jnani. It is through Jnana, knowledge, derived from meditation on the higher truths of religion and philosophy and on the highest Truth of one's own reaity (which teaches man how to understand himself and the projection of his own mind, viz, the Jagat- the world) that the Sai within is cognized.
Baba is not only the goal of Jnana, He is Jnana personified - that is Jnanaswarupa. He was a precocious child, revered as 'Guru' by His toddler comrades of the village; He knew far more than His teachers at school, where He was known as "Brahma Jnani", He who had known the Reality- the Brahman. He threw away His books even when He was in the V Form of the High school and has not had contact with study, since then. Baba's writings and discourses and conversations reveal a mastery of Scriptures and Sastras, which only a Jnanaswarupa can claim. Intricate points that escape experts are noted by Him and clarified at all Sessions of the Prasanthi Vidwan Maha- sabha.
"Sai Isa" is the transcendent and permanent Divinity of which the manifested beings are only transient and contingent modifications, modifications that can in no way affect Him.