The Bodhisatta was once a king. Some men were robbed in a forest and they chased after the thieves. They saw three men plowing a field and believed they were the thieves in disguise, so they hauled them off to prison.
One day a country woman stood outside the palace loudly crying that she needed her husband. The Bodhisatta brought her in to talk, and she told him about the three men wrongly captured as thieves: they were her husband, son, and brother. The Bodhisatta agreed to let her choose one man to go free, and she chose her brother. Surprised by her answer, the Bodhisatta asked her why choose a brother, the least important of the three relations. She answered that she could find a new husband and have another son, but she could never get another brother. Impressed by her wisdom, the Bodhisatta set all three men free.
In the Lifetime of the Buddha
Three men were mistaken for thieves, wrongly incarcerated, and then saved by a woman, just as had happened in the past. When the Buddha heard some of his disciples praising her, he told them this story so they knew that the same thing had happened to earlier births of the same four people.