Among the chassidim of the Tzemach Tzedek was a businessman whose dealings took him to the business centers of the large cities of Russia as well as to several foreign capitals. As time went by, he became increasingly uncomfortable in these environments with his long black coat and chassidic hat. Gradually, he adopted a more secular mode of dress on his business trips. Of course, he continued to travel to his Rebbe in traditional chassidic garb.
Then, one day, he appeared in Lubavitch in his businessman's attire. "Rebbe," he announced, "I've decided to put an end to my hypocritical behavior. This is how I dress on all my travels, so why delude myself and others with my chassidic clothes?"
"Reb Yankel," said the Rebbe, "do you think that I was not aware that you dress differently in Leipzig and Paris than you do in Lubavitch? But I thought that here you showed us your true self, and there you were the hypocrite...."
The Week in Review (as related by chassidim)