What is the fundamental definition of birth and death provided in the text, and how does it apply to ordinary people versus saints?

Chapter 43 provides a clear definition, stating that the union of the body and senses is birth, while the separation of the body and senses is death. This binding and loosening of the bond is an inseparable cycle for most beings. However, this definition applies differently to saints. For them, birth and death are considered 'false imaginations.' The text explains that saints incarnate by their own will for the welfare of devotees and are not touched by this cycle in the same way. They have already 'killed death' and placed their feet on the head of Time, so the fear of death is like dust before them.