In the previous chapter, it was argued that a key experiential schema governing the use of ṭum’ah is that of infection. In this chapter, this relationship will be examined in more detail, highlighting the complications involved when articulating the experience of disease in language. These difficulties will be demonstrated through an examination of biblical ṣara‛at and its common translation as “leprosy.” This specific case will serve as a point of entry for examining the awareness of contagion more generally in ancient Israel and neighboring cultures, particularly as expressed in the terminology of pollution. This line of inquiry will provide the necessary background to reevaluate attempts to downgrade the severity of biblical diseases as sources of mere “ritual” impurity.