What is the philosophical basis for the claim that saints like Sai Baba are beyond the normal cycle of birth and death?

Chapter 43 explains this by defining birth as the union of body and senses and death as their separation. For enlightened beings who incarnate by their own will for the welfare of devotees, this cycle is not binding; they 'place their feet on the head of Time.' Sai Baba is identified as the 'complete Supreme Brahman,' for whom the world is an illusion and consciousness of the body is non-existent. His physical form is described as merely an 'adjunct.' Therefore, as Chapter 43 asks, 'for him who does not know the birth of the body, how can there be death for his body?' His seeming death is understood as a conscious merging back into his true, unmanifest state, thereby transcending the material plane entirely.