How could leprosy affect clothing?

Critics point out that leprosy cannot affect clothing –only skin. From this, they infer that the Bible is clearly a pre-scientific and pre-medical book, which is antiquated in its understanding of disease and medicine.

The word translated as “leprosy” (ṣāra‘at) is actually a general term that refers to generic diseases and growths of various kinds.^[1] It could include modern day Hansen’s disease, but it isn’t limited to this. Indeed, Hansen’s disease wasn’t classified as such until 1873. Consequently, “most modern commentators and lexicographers have abandoned this translation [i.e. “leprosy”], maintaining that the term refers to a number of infectious diseases. The term would include leprosy, but it should not be restricted to it.”^[2]

This explains why the term could even be associated with mildew or the rot on a house (Lev. 14:34). When this term is used of skin (see Lev. 13:6), it can sometimes clear up in seven days, which is never true of Hansen’s disease. Therefore, the references to this spreading on clothing probably refer to a general flaking or distorting of the garment, as it does in affecting people’s skin.

^[1] R. K. Harrison, Leviticus: An Introduction and Commentary, vol. 3, Tyndale Old Testament Commentaries (Downers Grove, IL: InterVarsity Press, 1980), 139–140.

^[2] Mark F. Rooker, Leviticus, vol. 3A, The New American Commentary (Nashville: Broadman & Holman Publishers, 2000), 187.