NUM99 We should learn the extent of the prohibition against loshon hora from Miriam's speaking against Moshe. Miriam heard from Moshe's wife, Tzipora (see Rashi for the reason why she was referred to as a Cushite), that Moshe had separated himself from her. Miriam felt that Moshe's behavior was improper and related this to her brother Aharon. The Chofetz Chayim (Shmiras Haloshon 2:18) writes that from these verses [12:1-3] we learn a number of principles concerning loshon hora: 1) The prohibition against speaking loshon hora applies even when the person spoken against is very humble and does not mind if others speak against him. For this reason, immediately after Moshe was spoken against the Torah states that he was humble. 2) Even if you have done many favors for another person, it does not give you the right to speak against him. Miriam helped save Moshe's life but was still punished for her loshon hora. 3) The prohibition against loshon hora applies even if you do not publicize the loshon hora but will only relate it to one person, and that person is a relative who will not repeat it to anyone else. Miriam told the loshon hora only to her brother Aharon who would not publicize it. 4) If you say about a truly great man that his behavior would only be proper if he were on a higher level, but on his present level his behavior is improper, it is considered loshon hora. Miriam felt that Moshe was wrong for separating himself from his wife. She erred, since Moshe's level of prophecy was such that at any moment God could communicate with him and his abstention was proper.