Mendel Berger was a dealer in remnant materials. Two weeks prior to Passover, his poor uncle approached him and said, “Dear nephew, every year at this time you give me material for a garment without charge. This year, however, my conditions are better and I want to purchase the cloth.” Berger allowed his relative to select whatever he wanted and charged him a minimal price. The uncle left very pleased and promised to pay in a few days. “Why do you sigh, Mendel?” his wife asked. “You should be content that he is going to pay this time.” “On the contrary,” Mendel replied. “When my uncle was poor, I used to give him material without money. It was usually something that was difficult for me to sell. In this way, I performed a good deed and it did not cost me much. Now when he came to purchase some material for money, I had to let him choose the finest piece of cloth at less than my cost. I doubt he will remember to pay ...