Among the many laws detailed in Mishpatim is the law not to accept a false report (23:1). Why does the Torah need to give us these explicit prohibitions? Aren’t these rules rather obvious?
Oznayim LaTorah suggests that this rule is an extension of the laws of lashon hara (slander). “You shall not be a talebearer among your people” is meant to stop negativity at its source by not allowing evil speech in the first place. By expanding upon the initial law and now addressing the people on the receiving end of the lashon hara, the Torah is sensitizing us to how damaging negative words can be both to the recipient and the speaker. Not believing lashon hara is the way to react upon hearing it and certainly absolves us of the wrongdoing; but standing by as it’s spoken is still allowing negative speech to be put out there for consumption, whether in a personal or court setting. It is for this reason that we have a collective responsibility to prevent derogatory words from being spoken, even if no one believes them. Negative comments only create negative energy, and our world needs as much positivity as we can deliver.