How did Sai Baba reveal Sapatnekar's entire life story to him in a miraculous way?

As detailed in Chapter 48, Sai Baba employed a unique and indirect method to reveal his omniscience to Sapatnekar. While Sapatnekar was holding his feet, a shepherd (Dhangar) woman arrived and began massaging Baba's waist. Baba then started a conversation with her, but the story he told was a detailed account of Sapatnekar's own life, including the painful memory of his late son's death. Sapatnekar listened in shock and wonder, realizing that although the story was ostensibly for the woman, every word was his own biography, proving Baba knew everything about him.