A merchant, having sold all his wares at the fair and filled his moneybags with gold and silver, was eager to return home before nightfall. He packed his trunk with the money, loaded it onto his horse, and set off.
At noon, he stopped to rest in a town. When he prepared to continue his journey, the stable-boy brought out his horse and said, "Sir, a nail is missing from the shoe on the horse's left hind foot."
"Let it be," replied the merchant. "The shoe will surely hold for the six miles I have left. I am in a hurry."
In the afternoon, when he stopped again to feed his horse, the stable-boy came to him and said, "Sir, a shoe is missing from your horse's left hind foot. Shall I take him to the blacksmith?"
"Let it still be missing," the man answered. "The horse can manage the remaining couple of miles. I am in haste."
He rode on, but soon the horse began to limp. Not long after limping, it began to stumble, and shortly after stumbling, it fell down and broke its leg. The merchant was forced to leave the horse where it fell, unbuckle the trunk, carry it on his back, and walk home on foot. He did not arrive until very late at night.
"And all this disaster," he said to himself, "was caused by that unlucky nail."