Why was Amir Shakkar told to stay in the Chavadi, and what were the conditions like there?

According to Chapter 22, Sai Baba instructed Amir Shakkar to stay in the Chavadi as a remedy for his rheumatism. The conditions there were extremely harsh. The text describes the Chavadi as an old, dilapidated building where lizards and scorpions lived freely. It was filled with garbage, had seventeen knee-deep holes, and was plagued by dampness from rain and cold winds. Lepers also stayed there, and the place was described as a 'total chaos of wind and cold'. Despite Amir's misery, Baba's firm word was that he must stay there, suggesting the purpose was a test of faith rather than a search for physical comfort.