Why did Amir Shakkar agree to stay in the dilapidated Chavadi for nine months, despite his rheumatism?

Amir Shakkar's decision to stay in the miserable Chavadi was an act of profound faith in Sai Baba. As Chapter 22 explains, although the external conditions were completely contrary to his physical well-being, especially with his rheumatism, he had "certain faith" internally. Baba's firm words telling him not to worry about the wind, rain, or dampness were his only "medicine." Amir accepted Baba's instruction as the "Great Prasad" and, as a result of this unwavering trust, he stayed there happily for the ordained nine months, and everything went well for him.