Rav Huna, the third-century head of the Babylonian academy at Sura, owned a vineyard and hired laborers to work it. One harvest day he refused to share wine with the men who were working under the sun for him. It was not generosity he owed them — the wages had been agreed — but a custom had grown up among Jewish vineyard owners to give workers a cup from the very casks they had helped to fill.
That night, when Rav Huna went to check his cellar, he found that four hundred of his casks had turned sour at once. The loss was enormous. He understood immediately what had happened. His own miserliness — a cup withheld at the height of the labor — had spoiled an entire year's production.
He did teshuvah. He went back to the laborers, apologized, gave them wine from his reserves, and undertook to share his casks openly from then on. When he returned to the cellar, the casks that had turned to vinegar had turned sweet again. Four hundred casks of wine — ruined by a small refusal and restored by a small repentance.
Gaster's Exempla of the Rabbis (1924, No. 177, additions) preserves this episode as a micro-drama of the economic dimensions of teshuvah. Heaven does not always punish miserliness with lightning. Sometimes it simply lets the consequences ripen — or sour — in the cellars we already own.