How did Sai Baba prove to Cholkar that he knew about his secret vow?

Sai Baba demonstrated his omniscience to Cholkar in a subtle yet powerful way. After Cholkar had fulfilled his vow and was visiting with another devotee named Jog, Baba gave a specific instruction. As detailed in Chapter 15, Baba told Jog, "Give him cups of tea, well-filled with sugar." This was remarkable because Baba himself did not drink tea, and more importantly, it directly referenced the very substance Cholkar had secretly renounced. Hearing these meaningful words, Cholkar was amazed and moved to tears, as it was a clear sign that Baba was aware of his private vow, the long delay, and the penance he had undertaken, thereby confirming and deepening his faith.