A pertinent illustration of the sin of evil talk comes in a story about the great Chafetz Chayyim.
One evening he was out for a walk and he met someone who was new in town. The stranger had no idea who the rabbi was and asked him, “Can you tell me, my man, where your rabbi, the righteous author of the book Chafetz Chayyim, lives?”
The Chafetz Chayyim replied, “Firstly, he is not much of a rabbi, and secondly, he is not so righteous…” The stranger was shocked and said, “What are you saying? Everyone knows he is a great rabbi and he is very righteous.” The Chafetz Chayyim said, “Don’t listen to what people say. They don’t know what they are talking about!”
The stranger became irate and slapped him across the face. The Chafetz Chayyim said nothing but continued with his walk.
When he got home he found the stranger sitting in his house, waiting to talk to him. When the visitor realised that the man he had slapped was the great Chafetz Chayyim himself he was so upset that he fainted.
The Chafetz Chayyim revived him and said quietly, “You have done nothing wrong. I deserved the slap you gave me, and it taught me a lesson. I now know that not only must one not speak badly about others; one must also not speak badly about oneself…”