Source : Webster's Revised Unabridged Dictionary (1913)

Commination \Com`mi*na"tion\, n. [L. comminatio, from comminari
   to threaten; com- + minari to threaten: cf. F. commination.]
   1. A threat or threatening; a denunciation of punishment or
      vengeance.

            With terrible comminations to all them that did
            resist.                               --Foxe.

            Those thunders of commination.        --I. Taylor.

   2. An office in the liturgy of the Church of England, used on
      Ash Wednesday, containing a recital of God's anger and
      judgments against sinners.

Source : WordNet®

commination
     n 1: prayers proclaiming God's anger against sinners; read in the
          Church of England on Ash Wednesday
     2: a threat of divine punishment or vengeance