How did Sai Baba's personal conduct challenge the prevailing caste system and notions of ritual purity?

Sai Baba fundamentally challenged the rigid social structures of his time, particularly the caste system and concepts of ritual purity. Chapter 7 explains that for him, caste did not matter in the slightest, whether one was a Shudra or an outcaste. This is powerfully illustrated by the fact that the most elite Brahmins and keepers of sacred fires (Agnihotris) would abandon their pride in ritual purity to prostrate before him. He held no ego regarding the body and was the same to all castes, making no distinctions of birth. His mind felt no disgust even if a dog were to contaminate food, demonstrating a profound detachment from the social rules that governed purity and pollution, and showing that true holiness lies beyond such distinctions.