Source : Webster's Revised Unabridged Dictionary (1913)

Job \Job\, n.
   The hero of the book of that name in the Old Testament; the
   typical patient man.

   {Job's comforter}.
   (a) A false friend; a tactless or malicious person who, under
       pretense of sympathy, insinuates rebukes.
   (b) A boil. [Colloq.]

   {Job's news}, bad news. --Carlyle.

   {Job's tears} (Bot.), a kind of grass ({Coix Lacryma}), with
      hard, shining, pearly grains.

Comforter \Com"fort*er\, n.
   1. One who administers comfort or consolation.

            Let no comforter delight mine ear But such a one
            whose wrongs do suit with mine.       --Shak.

   2. (Script.) The Holy Spirit, -- referring to his office of
      comforting believers.

            But the Comforter, which is the Holy Ghost, whom the
            Father will send in my name, he shall teach you all
            things.                               --John xiv.
                                                  26.

   3. A knit woolen tippet, long and narrow. [U. S.]

            The American schoolboy takes off his comforter and
            unbuttons his jacket before going in for a snowball
            fight.                                --Pop. Sci.
                                                  Monthly.

   4. A wadded bedquilt; a comfortable. [U. S.]

   {Job's comforter}, a boil. [Colloq.]

Source : WordNet®

Job's comforter
     n : someone whose comfort is actually discouraging