Leviticus 19:9-10 and Deuteronomy 24:19 lay out a peculiar agricultural law. When you harvest your field and forget a sheaf behind you, you are forbidden to go back for it. It belongs now to the stranger, the orphan, the widow. The commandment is called shikhecha, the law of "forgetting," and it has a strange geometry: you can only fulfill it by accident.
Gaster's exemplum No. 107 tells of a man who came home from his field one evening and suddenly remembered — with a jolt — that he had left a bound sheaf behind in the stubble.
Most farmers in that moment would feel frustration: the labor wasted, the grain lost. But this man laughed with joy. He had not merely lost a sheaf; he had performed a mitzvah that most of his neighbors would never be lucky enough to stumble into. The law of the forgotten sheaf cannot be fulfilled by planning. The instant you turn around and say, "I'll deliberately leave that one," the opportunity is gone. Only honest forgetfulness counts.
So he went back inside, prepared a feast for his household, and celebrated the accident. Somewhere in his field, a hungry stranger would arrive in the morning and find bread waiting. And the farmer had done nothing for it except to be slightly absent-minded at the right moment.
The rabbis loved this story because it proves a profound Jewish point. Not every act of charity requires planning. Sometimes the Torah is built into the world itself, waiting for your forgetfulness to release it.