LEV645 … one who sees his neighbor sinning secretly and reveals it to others, sins thereby. For it may be that the sinner has since repented of his evil way, and he should have revealed it only to a discrete sage, who would not shame him so that he might turn from his repentance. He should, however, keep himself from his company until he knows that he has repented of his evil way. And if the sinner is a Torah scholar and a God-fearing man, he should be considered to have repented of a certainty (Berachos 19a), and even though his evil inclination may have ensnared him once, he assuredly regretted it thereafter. The slanderer is punished for the injury and shame he caused his fellowman, and in addition, for having rejoiced in his neighbor's shame, for it is written [this verse]: "And you shall love your fellowman as yourself." Just as one is solicitous of his own honor, he should be solicitous of his fellowman's (see Avos 2:10). And it is written (Mishlei 17:5): "He who rejoices in calamity shall not go unpunished." And there is a respect in which the sin of one who slanders with the truth is greater than that of one who slanders falsely. For when one speaks the truth against someone, he is apt to be believed and the object of the slander may be demeaned in the eyes of men even after he has regretted his sin and repented of it and been forgiven. But false slander is sensed as such by most people, and they will not believe it. For the most part, however, offenses through falsity carry a greater penalty than offenses through truth.