The Gemara in Megillah (13b) says that when Yaakov encountered Rochel at the well, he asked her to marry him. She replied in the affirmative but warned Yaakov that her father Lavan was a trickster and that Yaakov would never be able to outfox him. Yaakov responded that if Lavan deals with him fairly and honestly, he will happily respond in kind. However, if Lavan attempts to deceive him, he will be Lavan’s “brother” in deceit and beat him at his own game.
Rav Yitzchak Zilberstein relates a fascinating legal query that he once received. A young man entered a barber shop and asked the barber to give him an exceptional haircut, explaining that he was a choson who was getting married that evening. The unscrupulous barber, aware that there were no other barbers in the area and realizing that a chosan on his wedding day would be pressed for time, decided to take advantage of his vulnerable customer by informing him that the fee for the haircut would be double the usual price.
The chosan was shocked and disgusted by the barber’s greed yet had no choice but to agree to the unfair demands. However, at the end of the haircut, when it was time to pay, he exclaimed, “Why should I pay you even a penny for this haircut? Don’t you know that I have miraculous hair that grows back to its original length just hours after it’s been cut? Your haircut hasn’t helped me whatsoever, and I don’t owe you anything for it.” The astonished barber assured the chosan that if he returned in the afternoon looking as he did when he entered, he would happily give him another haircut free of charge.
The chosan approached Rav Zilberstein with the following legal question: Since the barber unfairly forced him to pay double the regular price, was he permitted to send in his identical twin brother (who had not recently taken a haircut) to receive for free the second haircut that he was unjustly forced to pay for? Although the barber certainly did not deserve any compassion and the chosan’s quick thinking in his pursuit of justice was quite original, Rav Zilberstein nevertheless was not keen on his proposed method of being the barber’s “brother” in deceit. (R’ Ozer Alport)