This story is told about Rav Avraham Yehoshua Hershel of Apt, who lived in Europe before the advent of the telephone and other speedy methods of communication.
Once a merchant from Russia planned to take a long trip to Germany to purchase goods. He hired a coachman with a horse and wagon to make the trip with him. He took along a large sum of money with which to purchase the merchandise and placed it in a box under his seat.
After many weeks of traveling, they neared the city of Apt where Rav Hershel lived. Before entering the city, the coachman removed his work clothes and donned his Shabbos clothes. Turning to the merchant, the burly driver said, “This is where we change places. I am now becoming the merchant and I will take possession of your money. Nobody knows us in this city so your hollering won’t amount to anything.”
The merchant was frightened and realized that he couldn’t do anything, for the driver was a powerfully-built man. In desperation, he inquired where the local rav lived. He was directed to Rav Hershel’s home. When the merchant poured out his woes, the rav ordered the coachman to appear before him to stand trial. He was to appear at a din Torah.
When the coachman appeared, he raised a loud cry, “What does this thief want from me? I am the true merchant and here is all the money that I brought with me. Please tell him to stop annoying me.”
Rav Hershel was perplexed. While he could tell from the fine features and behavior of the merchant that he was the true merchant and being victimized by a scoundrel, he had no proof.
Suddenly, he had an inspiration. Turning to both parties, he said, “I will have to postpone this hearing until later in the day. I have something important to attend to.”
As the two people walked away from him, Rav Hershel suddenly shouted, “Hey, coachman!”
Accustomed to being called by that name, the real coachman turned around unwittingly and asked, “What do you want?”
“Aha,” said Rav Hershel, “then you are the real coachman. Return the money to the merchant. Otherwise I’ll have you locked up as a thief!”