The Torah says (Numbers 16) that Korah led a rebellion against Moses and Aaron, and that the earth opened and swallowed him. What the Torah does not say — what the midrash fills in — is what Korah had to lose.
Three hundred mules, the tradition reports, were required simply to carry the keys to Korah's treasure houses. Not the treasure itself. The keys.
Where did such wealth come from? The midrash traces it back to Joseph. While he ruled Egypt, Joseph gathered the silver and gold of the world into three great towers for Pharaoh — stockpiled wealth from the famine years, when every nation came to Egypt to buy grain and left its treasure behind. The contents of one of those towers, generations later, had passed into Korah's hands. The second tower, the midrash says, was discovered much later by the Roman emperor Antoninus. The third tower is still hidden, reserved for the Mashiach.
Meanwhile, the midrash notes grimly, Korah's own children had nothing. His hoard did not extend to his own family. This becomes significant when the midrash rehearses the immediate cause of the rebellion. A widow had come to Moses with a tithing dispute. Korah, arguing the widow's case with theatrical zeal, used her suffering as a wedge to attack Moses and Aaron's priestly authority. He framed himself as defender of the poor while his mules staggered under the weight of his keys.
Pride, the tradition says, killed Korah. He had more wealth than anyone. He had earned none of it. And rather than share it, he used a widow's lamb to destabilize Moses. The earth that swallowed him was simply heaven giving him the small, dark room his greed had already built.
Gaster's Exempla (no. 389, 1924, from the Ben Attar collection) preserves this story because it insists that the Torah's wealthiest villain died of one specific sin. Not unbelief. Not even rebellion. Pride in a fortune he did not know how to carry.