How did Sai Baba's behavior challenge the caste system and notions of ritual purity during his time?

Chapter 7 of the Shri Sai Satcharitra illustrates how Sai Baba actively dismantled social hierarchies and rules of purity. The text states that caste did not matter to him in the slightest, as he had no ego regarding his body. A powerful example given is how the most respected Brahmins and Agnihotris (keepers of sacred fire), who were typically very strict about ritual purity, would abandon their pride and prostrate before him. This amazed onlookers. Moreover, the chapter mentions that his mind felt no disgust even if a dog put its mouth into the food, demonstrating a complete detachment from the conventional purity standards that were deeply ingrained in society.