Amazing! I've been speaking prose for more than forty years without ever knowing it.
About 2,100 years ago, Rabbi Simon ben Shetah was in the market for an ass. After some bargaining with its Arab owner—and probably some refreshment—he brought his new beast home, complete with its harness. When he arrived, his students helped him with it. Suddenly, they shouted, “Rabbi, God's blessing enriches.” 2 Suspended around the animal's neck, they had discovered a precious gem. 3
Sometimes you get more than you pay for.
But Rabbi Simon was a member of a wealthy family, the brother of Queen Salome Alexandra of Judaea. Perhaps that and his renowned piety help explain the rest of the story: Declaring, “I bought the ass and not the gem, ” Simon returned the gem to its owner.
Of course, Simon wanted to teach honesty and kindness. He knew that keeping the gem would likely have done great harm to its rightful owner. But sometimes that is not true. Sometimes, you get more than you pay for and you harm no one if you keep it. In some cases of reconciliation ecology, Simon would have decided that you must keep the precious bonus. Giving it back would do a lot of harm. These are the happy accidents.