What is "Cheres"?
Ibn Ezra: Some say that it is like "[uva'Garav] uve'Chares" (boils 1 that are dry like earthenware).
Metzudas David: It is earthenware.
Did he take boils to scratch himself?! Ibn Ezra must mean that the verse hints that his boils were like Cheres. (PF)
What is the meaning of "Lehigared"?
Rashi: It is to scrape, like Goredo u'Ma'amido Al Gildo (Rosh Hashanah 27b).
Ibn Ezra: It is to scratch. There is nothing like this in Tanach.
Why did he sit in ashes?
Ibn Ezra #1: This is the way of mourning - "va'Ychas Sak va'Yeshev El ha'Efer" (3:6).
Ibn Ezra #2: Some say, it was to cool the boils 1 .
Devar Eliyahu: Ashes, which fell from the scabs of the boils, surrounded him.
Malbim citing a Midrash: His upper half was dry boils - for this, he scratched with earthenware. His bottom half was moist boils - for this he sat in ashes, which draw out the moisture. This was like one stung by a wasp and scorpion (Chagigah 5a; the cure for one is dangerous for the other).
Ibn Ezra: This opinion must bring a proof that the boils were moist and hot!
