Can you recount the specific incident involving Bade Baba during the Diwali feast?

Certainly. Chapter 23 recounts a specific event that highlights Bade Baba's unique importance. During a festival like Diwali, plates filled with delicacies were served and the rows of devotees were ready to eat. However, Bade Baba went away in a huff. Because of Sai Baba's rule that He would not eat unless Bade Baba took a morsel first, the entire feast was put on hold. If Sai Baba did not eat, nobody else could. Everyone was held up until they searched for Bade Baba and brought him back. Only after he was seated in the row did Baba, and subsequently everyone else, begin the meal.