NUM380 If a person suffered a loss of income and he does not know who caused it, then it is forbidden for him to suspect any Jew, for we may not freely label people reshaim. This halachah would apply, for example, to one who loses the contract he previously had with a government official, and does not know if someone informed on him to his boss; or if his boss decided of his own accord to fire him; or if something else happened. Regarding cases like these, the pasuk says בְּצֶ֖דֶק תִּשְׁפֹּ֥ט עֲמִיתֶֽךָ׃, “Judge your fellow favorably” (Vayikra 19:15). (However, if there is clear evidence that proves that a particular person was responsible for what happened--and the evidence meets the criteria below that delineate what constitutes clear evidence--then he is permitted to believe in his heart that this person was in fact responsible. Nevertheless, it is forbidden for him to harm that person based on this evidence, as we will explain later.) Even if he heard that a particular individual was responsible for causing him the damage, he may only consider the possibility that the information is true, and may not definitively believe it to be the truth. Furthermore, even if people confronted the individual and told him that he was rumored to have committed a terrible offence by causing harm to a fellow Jew, and the person was silent in the face of their accusation, one still cannot assume that his silence proves that the accusation is true. Although it is, in fact, a mitzvah for one to clear himself of suspicion and explain to the person who suspects him why he is innocent--as the pasuk says: וִהְיִיתֶ֧ם נְקִיִּ֛ים מֵיְהוָ֖ה וּמִיִּשְׂרָאֵ֑ל “And you shall be clean [of suspicion] before Hashem and Yisrael” (Bamidbar 32:22)--it is nevertheless possible that he felt that in this case it was better to keep quiet. Perhaps he realized that these people have so firmly believed the lashon hara and decisively concluded that he is indeed the responsible party, that they will not accept any answer he gives. He therefore decided that it is better for him to remain silent and be among those “who are insulted but do not insult, who listened to their disgrace and do not respond.” [apparently referencing Yoma 23a—AJL].