How does the text explain the nature of birth and death from a philosophical standpoint?

Chapter 43 presents a distinct philosophical definition, stating that the union of the body and senses is birth, while their separation is death. This binding and loosening are what we perceive as the cycle of life. However, the text clarifies that for an enlightened being who has transcended bodily consciousness, this definition is irrelevant. For one who is the complete Supreme Brahman, the world itself is an illusion, so the consciousness of the body, and by extension its birth or death, does not exist. Death is described as a mere characteristic or state of happiness for the physical body, not a reality for the soul of a saint.