A pious man on a journey found a cave in the mountains. He entered. Inside was a small pool of water, and behind it, a narrower dark inner chamber. He stepped into the inner chamber to rest. Before he could leave, he heard footsteps and hid himself to watch.
A man came into the cave, undressed, plunged into the pool for a ritual bath, dressed again, said his prayers, and left. As he had undressed, his purse had fallen from his garments and dropped to the stone floor unnoticed.
A moment later, a second man entered. He saw the purse lying on the ground. He picked it up and hurried out with it.
Not long after, a third man entered. He too undressed and bathed. While he was dressing, the first man returned, having discovered his loss and retraced his steps. Seeing only the third man, the first accused him of theft. The third protested that he had just come in. The first man, enraged, drew a weapon and killed him on the spot.
The pious man, hidden in the inner chamber, was horrified. A purse had gone astray, a stranger had pocketed it, and an innocent bather had been murdered in the place of the real thief. The world looked deranged.
He fell asleep in the cave, still shaken. In a dream an angel came to him and explained. The third man, apparently innocent, had years before murdered the father of the first man and gone unpunished. The first man had now, without knowing it, avenged his father's death. As for the purse, it had once belonged to the father of the second man, and the first man had stolen it from him long ago. By losing the purse today, the first man had returned stolen property to its rightful heir. Three generations of unfinished accounts had been closed in the space of ten minutes. The Exempla, gathering the story from diverse Gaster manuscripts, uses it to teach one of the tradition's hardest doctrines. The ledger of the world is older than any single generation can see.