How does Sai define the concepts of birth and death?

As explained in Chapter 43, birth and death are viewed as intrinsically linked and inseparable. Birth is defined as the union of the body and the senses, while death is simply their separation. This process of binding or loosening the bond between body and senses is what constitutes birth and death. However, for those who are spiritually realized, both birth and death are considered to be false imaginations. The text emphasizes that death is a natural characteristic of the body, whereas life is a modification of it.