How did Sai Baba's interaction with Cholkar demonstrate his omniscience?

Sai Baba demonstrated his omniscience to Cholkar through a simple yet powerful act involving tea. According to Chapter 15, Cholkar had secretly given up sugar as a personal penance while waiting to fulfill a vow. When he finally came to Shirdi and completed his offering, Baba, who did not drink tea himself, specifically instructed Mr. Jog to give Cholkar 'cups of tea, well-filled with sugar.' This instruction, coming at that precise moment, stunned Cholkar. Baba then confirmed this was no coincidence, stating, 'The state of your mind at the time of the vow, and the penance of the long delay— Though you kept these secret, all of it is known to me.' This proved that Baba was fully aware of Cholkar's thoughts, secret vows, and actions, despite the physical distance between them.