How does the story of Cholkar's vow serve as a testament to Sai Baba's omniscience?

The story of Cholkar is a powerful testament to Sai Baba's omniscience because Baba knew every secret detail of Cholkar's private spiritual practice. Chapter 15 highlights that Cholkar had made a vow to avoid sugar until he could visit Shirdi, a vow he kept secret. Baba demonstrated His all-knowing nature not through words alone, but through a specific, timely action: ordering tea "well-filled with sugar" for Cholkar at the very moment his vow was fulfilled. Baba then verbally confirmed this, stating, "Your vow of sugar has been accepted...Though you kept these secret, all of it is known to me." This proved He was aware of the vow, the mental state behind it, and the long, difficult delay Cholkar had endured.