The other foot, fast fixed on his shield,
  Whenas no strength, nor strokes mote him constrain
  To loose, nor yet the warlike pledge to yield,
  He smote thereat with all his might and main,
  That nought so wondrous puissance might sustain;
  Upon the joint the lucky steel did light,
  And made such way, that hewed it quite in twain;
  The paw yet missed not his minished might,
But hung still on the shield, as it at first was pight.

Book I, Canto XI