Why did Kashiram fight so fiercely over a small bundle during the robbery, and what did it contain?

The small bundle was incredibly dear to Kashiram, prompting him to risk his life for it. The introduction in Chapter 0 reveals that the bundle did not contain treasure as the thieves suspected, but rather powdered sugar. This sugar was not for his own consumption; Kashiram carried it because a saint named Janakidas Baba had advised him to feed sugar to ants. Therefore, the bundle represented a sacred vow and an act of service, which is why he was determined not to let the thieves take it from him, no matter the cost.