The Lord will smite thee with the botch of Egypt,.... Which some understand of the leprosy, Of that sort of it called "elephantiasis", frequent among the Egyptians; See Gill on "Le 13:2". Thevenot relates, that when the time of the increase of the Nile expires, the Egyptians are attended with sharp prickings in their skin like needles.
So Vansleb says ,"the waters of the Nile cause an itch in the skin, which troubles such as drink of them when the river increases. This itch is very small, and appears first about the arms, next upon the stomach, and spreads all about the body, which causes a grievous pain; and not only the river water, but that out of the cisterns drank of, brings it, and it lasts about six weeks.'
'Though some take this botch to be the botch and blain which the Egyptians were plagued with for refusing to let Israel go, Ex 9:9;and with the emerods; or haemorrhoids, the piles, a disease of the fundament, attended sometimes with ulcers there; see 1Sa 5:9;and with the scab and with the itch: the one moist, the other dry, and both very distressing:whereof thou canst not be healed; by any art of men; which shows these to be uncommon ones, and from the immediate hand of God.
Apud Scheuchzer. Physic. Sacr. vol. 3. p. 426, 427. Relation of a Voyage to Egypt, p.