I've heard reports that miracles happen in Shirdi. Could you describe the miracle involving grapes that Boss Dharamsee experienced?

Certainly. As recounted in Chapter 35, a devotee named Kaka brought grapes with seeds as an offering to Baba. When Baba began distributing them, he offered some to Boss Dharamsee, who disliked that variety. Troubled, he initially hesitated but eventually ate them at Baba's insistence. To his great surprise, the grapes he put in his mouth were completely seedless. When he asked another devotee, Tarkhad, about his grapes, Tarkhad confirmed his had seeds. This personal miracle amazed Dharamsee, who realized the 'strange power' of saints and how Sai knew the intent of his mind.