EXOD78 …tzaraat….has been variously translated as leprosy, skin disease, and scaly infection. Yes there are formidable problems in identifying it with any known disease. First, it symptoms do not correspond to Hansen's Disease, otherwise known as leprosy. Second, as described in the Torah, it affects not only human beings but also the walls of houses, furniture, and clothes. There is no known medical condition that has this property. Besides, the Torah is a book about holiness and correct conduct. It is not a medical text. Even if it were, as David Zvi Hoffman points out in his commentary, the procedures to be carried out do not correspond to those that would be done if tzaraat were contagious disease. [Rabbi David Zvi Hoffman, Commentary to Sefer Vayikra [Hebrew] (Jerusalem: Mossad Harav Kook, 1972), vol. 1, 253-55)]. Finally, tzaraat as described in the Torah is a condition that brings not sickness but rather impurity, tum'a. Health and purity are different things altogether. The sages decoded the mystery by relating this parasha to the instances of the Torah in which someone was actually afflicted by tzaraat. One happened when Miriam spoke against her brother Moses (Num. 12:1 – 15). Another occurred when Moses at the burning bush said to God that the Israelites would not believe in him. His hand briefly turned "as leprous as snow" [this verse]. The sages regarded tzaraat as a punishment for lashon hara, evil speech, speaking negatively about or denigrating another person.