Musar for Bava Kamma 198:29

The Talmud illustrates this point by various examples. In Baba Kama 99b we are told that a woman came to Rabbi Chiyah asking him to determine if a certain coin was sound. He told her that it was. The next day the same woman came back to him complaining that others had refused to accept the coin at full value. Thereupon Rabbi Chiyah instructed Rav, the keeper of his money, to give this woman a coin of his own to compensate her for what he perceived to be an error of judgment on his part. He asked Rav to record this transaction as a loss. The Talmud questions why this instance was different from the previously mentioned example of a professional money-changer who erred in his judgment and who had given his opinion without charging. Such a money-changer does not have to compensate the enquirer. The Talmud answers that Rabbi Chiyah did not have to make restitution, but that he acted לפנים משורת הדין, beyond what was demanded of him legally. He took his cue from Rav Yossi who interpreted Exodus 18,20: "You will inform them of the path they should take and the practices they are to follow" to mean that one should go beyond the demands of the law in dealings with fellow human beings.

We next have the injunction not to go about slandering people (19,16) This is also directed at judges. It includes a judge who did not preside over a certain litigation and who says that if he had been the judge in that case the decision would have been different. When the Torah phrases this injunction as "do not walk…" it is an allusion to people who are in the habit of going from one house to another exchanging gossip, etc. The Torah suggests to such people that if they do not want to become guilty of slander they should not keep "walking" around so much. Staying at home is a self-imposed "fence" around this law.