Since not merely by the fingers ought one to engrave it, but before this by the purpose of the heart with much faith. And if in this way thou hast marked it on thy face, none of the unclean spirits will be able to stand near thee, seeing the blade whereby he received his wound, seeing the sword which gave him his mortal stroke. For if we, on seeing the places in which the criminals are beheaded, shudder; think what the devil must endure, seeing the weapon, whereby Christ put an end to all his power, and cut off the head of the dragon.