The rabbis spoke often of two invisible forces that shape every human encounter: the good eye and the evil eye. The Maase Buch (No. 196) preserves a tale that illustrates the difference with terrifying clarity.
Two men — one generous, one envious — were brought before a king. The king made them a strange offer. "I will grant the first of you any wish," he said, "but whatever I give the first man, the second man will receive double." The two men stared at each other. The generous man saw an opportunity: if he asked for a house, his companion would receive two houses. If he asked for gold, his companion would receive twice as much gold. The generous man was delighted.
But the envious man was consumed by the evil eye. He could not bear the thought of his companion receiving more than him. He pushed to go first. The king nodded. "What is your wish?" The envious man thought carefully, his face twisting with spite. "Strike out one of my eyes," he said. That way, his companion would lose both.
The rabbis used this story to teach that the evil eye — the ayin hara (עין הרע) — is not merely jealousy. It is a force so corrosive that it will destroy the one who carries it before it harms anyone else. The man with the evil eye chose his own mutilation rather than see another person prosper. The Talmud teaches that the evil eye destroyed more people than the sword, because the sword can only reach those nearby, but envy follows its victim to the ends of the earth.