How did Sai Baba's 'word' serve as medicine for Amir's rheumatism, especially when the physical environment was so hostile?

The narrative in Chapter 22 explains that Baba's medicine was simply His word. The external conditions of the Chavadi—dampness, wind, and cold—were contrary to what would be considered good for rheumatism. However, Baba's firm instruction was not to heed these conditions. The true remedy was Amir's internal faith and acceptance of Baba's word as the ultimate medicine. By happily staying in the Chavadi for nine months based on this faith, despite the physical hardships, everything went well for him, demonstrating the power of belief and obedience over external circumstances.