108. O the divine mystery of that cross, on which weakness hangs, might is free, vices are nailed, and triumphal trophies raised. So that a certain saint said: “Pierce my flesh with nails for fear of Thee;” Ps. cxix. [cxviii.] 120. he says not with nails of iron, but of fear and faith. For the bonds of virtue are stronger than those of punishment. Lastly, his faith bound Peter, when he had followed the Lord as far as the hall of the high priest, whom no one had bound, and punishment loosened not him, whom faith bound. Again, when he was bound by the Jews, prayer loosed him, punishment did not hold him, because he had not gone back from Christ.