Can you walk me through the entire sequence of events when Baba decided to grind wheat?

Certainly. The event began when Sai Baba, to the surprise of onlookers, sat down at a grinding stone in the mosque and began grinding wheat by himself. As detailed in Chapter 1, news of this unusual activity spread, and four women ran to the mosque. They took the handle from Baba and began grinding together, singing his praises as they worked. Once they had ground a 'payali' (measure) of wheat, their thoughts turned to taking the flour for themselves. At this point, Baba, who had been silent, commanded them to take the flour and throw it on the village boundary. The women, though upset, obeyed, and it was later understood that this act drove a cholera epidemic from the village.