The botch of Egypt. — The “boil,” with which the Egyptians were plagued (Exodus 9:9, &c.) is the same word. (See also 2 Kings 20:7; Job 2:7.) Rashi says of this boil, “It was very bad, being moist on the inside, and dry outside.” A learned Dalmatian Jew, with whom I have read this passage, tells me that he has seen many cases of this kind among the Hungarian and Polish Jews, and that it prevails among them, being traceable partly to their uncleanliness.
Emerods — i.e., hœmorrhoids (as in 1 Samuel 5:6).
The scab. — In Leviticus 21:20; Leviticus 22:22 “scurvy.” It would make both a priest and a victim unclean, and unfit for the service of Jehovah.
The itch. — Here only. “A dry ulcer like a sherd” (Rashi).
Whereof thou canst not be healed. — Not that these things are in themselves incurable, but that they should have them incurably.