How did Sai Baba prove his omniscience to the skeptical Boss Dharamsee?

Sai Baba demonstrated his omniscience to Boss Dharamsee by directly responding to his unspoken, internal thoughts. As the narrative in Chapter 35 unfolds, Dharamsee, upon being offered grapes with seeds, silently questioned Baba's sainthood. He thought to himself, "If he is a saint, how does he not know That I do not like these grapes? Why does he force them upon me?" Baba, fully aware of this silent challenge, not only gave him more grapes but ultimately commanded him to eat them. When Dharamsee complied, the grapes miraculously became seedless. Dharamsee himself realized the truth, thinking, "Knowing the intent of my mind...they turn out to be seedless and beneficial." This direct and personal response to a hidden doubt served as undeniable proof of Baba's ability to perceive the innermost workings of a person's heart and mind.