How does the text philosophically define birth and death, and why are these concepts considered irrelevant for great saints like Sai Baba?

According to the teachings in Chapter 43, birth is defined as the union of the body and senses, while death is their separation. However, for great souls who incarnate by their own will for the welfare of devotees, these concepts are considered false imaginations. The text explains that such beings, who "place their feet on the head of Time," are not bound by the cycle of birth and death that governs ordinary life. Since they choose to incarnate and are not subject to the normal rules of existence, the very ideas of being born or dying do not apply to them in the same way. Death is described as a characteristic of the soul's nature, but these beings transcend even that.