'Purusha' is so called because of His residing in the Body, the pura. Baba says 'the entity that lives in the body' is the Purusha, the entity that lives in all bodies is the Purushothama, the chiefest person. Purusha is the Vyashti (individual) Purushothama is the Samashti (the collective). Purusha is the Tree, Purushothama is the forest. Baba is Purusha as well as Purushothama; Naraakara as well as Nirakaara. He has said 'the name of Sai fills the entire world, every inch of it, for there is no place where I am not; there is no Name which is not mine'.
In the Bhagawad gita, He declared to Arjuna, "As I transcend the perishable and as I am even higher than the imperishable, I am declared as the Purushothama (the Highest Purusha) by the world, as well as in the Veda. Without being deluded by my human body and human characteristics if a man knows Me as Purushothama, then he knows all; then, he worships Me with his whole being". Man cannot but seek and surrender to Purushothama, for the sense of the Holy is inherent in man. It is an inescapable impulse. That is why Baba, the Purushothama is worshipped and the worship is so fully rewarding.
Baba is also warning us against being misled by His human role; "I walk and talk and eat like you but remember always I am all Gods in one".