A young man traveling through the country met a young woman, and they fell in love. When he had to leave her town, they swore to wait for each other until they could marry.
"Who will witness our betrothal?" the young man asked.
Just then a weasel darted past them into the woods, and beside them stood a well of water. "See," the young man said, "this weasel and this well shall be the witnesses of our betrothal." And with that, they parted.
Years passed. The young woman waited. The young man did not. He married another woman, and they had a son, and the son was the delight of their lives. But one day the child lay down to nap in a field, and a weasel bit him in the throat, and he bled to death.
The parents were inconsolable. In time a second son was born, and gradually their grief lightened. But when that child could walk, he wandered out of the house alone, leaned over the edge of a well, lost his balance, and drowned.
Then the father remembered. He remembered the young woman, and the weasel, and the well. He told his wife what he had sworn and what he had broken. She agreed to a divorce. He traveled back to the town where he had left his first love — and found her, still there, still waiting. They married, and they lived in peace.
Heaven, the midrash teaches, keeps stranger records than we do. The witnesses you swear by when no one seems to be watching are the witnesses God assigns to remember.