If Sai Baba is beyond birth and death, why did he take a physical form and live in Shirdi?

Chapter 43 explains that great souls and avatars take on a physical form with the sole desire for the welfare and protection of their devotees. Their incarnation is for the purpose of helping others. The text states that Baba appeared in Shirdi, gathered by the past merits of his devotees, to fulfill this task of protection. Once this work was complete, he appeared to leave the body. His physical manifestation was not due to the normal karmic cycle of birth and death but was a willed act for the benefit of the people who sought him out.