In this Japanese folk tale, the whole story is built around the action of the old man in saving the little sparrow from being pursued and killed by the big black raven that is hunting it down:
One day the old man was sitting in front of his cottage, as he was very fond of doing, when he saw flying towards him a little sparrow, followed by a big black raven. The poor little thing was very much frightened and cried out as it flew, and the great bird came behind it terribly fast, flapping its wings and craning its beak, for it was hungry and wanted some dinner. But as they drew near the old man, he jumped up, and beat back the raven, which mounted, with hoarse screams of disappointment, into the sky, and the little bird, freed from its enemy, nestled into the old man's hand, and he carried it into the house.
The old man not only saves the little sparrow on this occasion, but provides a home for it with him and his wife, giving the sparrow a cage that it can stay in and be protected by. He does not keep the sparrow there all the time, and lets it out every day, but always allows it to return to the cage if the sparrow is nervous or in danger of being caught by a predator. It is this noble gesture that the tale is based around, and it is this noble gesture that gives the old man his reward, which could be argued to be a double reward, because not only does he gain great wealth, he is also rid of his greedy wife.