It seems counterintuitive for Baba to make someone with rheumatism stay in a damp, cold place. What was the spiritual purpose of Amir's ordeal in the Chavadi?

The spiritual purpose behind Baba's instruction for Amir to stay in the Chavadi was to teach the supremacy of faith over external circumstances. Chapter 22 explains that while the physical conditions were adverse, the true medicine was accepting Baba's word. The narrative states, "internally there was certain faith; because of that, everything went well." Though it felt like imprisonment, the proximity to Baba provided a "firm companionship with Sai." The nine-month stay was a profound test, demonstrating that unwavering obedience and faith in the Guru's command, even when it defies logic, is the path to both physical and spiritual well-being.