Could you explain why Sai Baba made Amir Shakkar stay in the dilapidated Chavadi to cure his rheumatism?

The provided text in Chapter 22 does not state the ultimate reason why Sai Baba made Amir Shakkar stay in the terrible Chavadi, but it implies it was a test of faith and a unique form of spiritual healing. Amir, who suffered from rheumatism, was given the instruction to stay there as his 'remedy.' Baba's firm words were the only medicine. Though the external conditions were contrary to physical healing, Chapter 22 notes that Amir had 'certain faith' internally. By accepting Baba's word as medicine, he stayed happily, receiving the 'Great Prasad' of Sai's company, suggesting the cure was spiritual and dependent on obedience rather than physical comfort.