Describe the purpose of Sai Baba's incarnation and why he chose to leave his body, according to this text.

The text explains that Sai Baba's incarnation was driven by a single motive. Chapter 43 states that beings like him incarnate 'with the sole desire for the welfare of devotees' and that he 'appeared in Shirdi for the sake of the devotees’ protection.' His purpose was entirely selfless and centered on his followers. The reason for his departure is framed as the completion of this divine work, as the text mentions, 'Now that the task for the devotees is over, they say he left the body.' However, his departure was not an abandonment but a transition into an unmanifest state where he could continue to reside in the hearts of his devotees and keep them spiritually awake.