NUM101 Envy and jealousy cause people to speak unfairly of others. Thus, Aaron and Miriam were the second and third most powerful figures in ancient Israel, and heroes to the entire Israelite community. But when they grew envious of their younger brother Moses--apparently for being accorded more prominence than they were [also, as my friend Daniel Taub points out, Moses had just appointed 70 elders, and perhaps they felt their status has been undermined.]--they spoke unfairly of him among themselves, an act for which Miriam (who seems to have instigated the slander; see [this verse]) was punished.