Laws of Rechilus / 1: 1-3 (82)

1. One who spreads gossip about his friend, transgresses the prohibition, Do not go as a gossipmonger, and it is a great sin that can destroy souls.

2. A rachil (gossipmonger) is one who tells his friend what another did or said against him, even when it is not inherently negative, and even when the subject himself would not deny it.

3. It is forbidden to tell Reuven that Shimon did or said something against him, even if he does not intend to cause hatred between them. Even if in his opinion Shimon’s actions are justified, if he assumes that it will cause hatred between them, it is rechilus.