Commentary Par XXII 16-18

For Dante's enemies, obviously, this sword will make itself felt all too soon, while for him it will be slow indeed in coming.

This feeling had already raced through Dante's veins.  Mattalia (DDP Mattalia.Par.XXII.16) indicates the second of Dante's 'political epistles' (Epist.VI.4, written in March of 1311), addressed to Henry VII, for the sword of God and vendetta.  The text speaks of the 'gladius Eius qui dicit: "Mea est ultio"' (the sword of Him who says, 'Vengeance is mine').