Isaiah 26:1

Hence, if they find anyone outside, they beat, wound and rob him by not believing in the true flesh of Christ that was nailed to the cross, from whom true blood flowed when pierced by a lance, and by not believing in the true God who bore a true soul and laid it down freely and raised it up freely. Isaiah prophesied about this city and, indeed, demonstrated with his finger, when he said, "Behold, our Savior is a strong city, fortified with walls and bulwarks."

For this reason, it seems to me that the wall represents the people who are acquainted with the one omnipotent God, having been brought near to the Word of the Father, about whom Isaiah prophesied, saying, "The Savior is our strong city. A wall and a bulwark is established in him." This indicates that Christ was shown to be equipped with a true soul and true flesh for the redemption of the world. But those who have already attained greater perfection, who are prepared to have their blood shed for the sake of his name, who by their own example offer unbelievers access to salvation, are compared with gates. For although the Word of God clothed himself with the nature of every human person for the liberation of the human race, it is nevertheless true that anyone becomes the wall or the gate of the prophesied city, that is of Christ, who, bearing God's image and holding fast to the true faith, merits with his holy works to contain the Word himself, as he promised through the prophet: "I will dwell within them, and I will be their God."

When Hezekiah, the king of Judah and son of Ahaz, was gravely ill and had learned of his coming death by the prophecy of Isaiah, he turned his face to the wall and wept bitterly. Immediately the Lord in his mercy not only averted the destruction of imminent death but also added fifteen years to the man's life. Then, at last, Hezekiah sang this song. Hezekiah, a holy man who reigned at that time over all of Israel, displayed the Lord's form: clearly he had every movement of body, soul and mind in subjection to himself, and he accepted the consequences of his infirmity and weakness. He knew without doubt through the prophetic message that the end of his life was approaching. For the longer we seem to live, the more indubitably is our future death foreknown to us. And if we turn our face to the wall when struck by the fear of death, that is, if we direct the vision of our hearts to the Savior, who is here represented by the wall because he is elsewhere called "a wall," we will be saved, inasmuch as he saves the faithful who dwell within him from a great many attacks. "In the city of our strength," says Isaiah, "is the Savior established as a wall and a fortress." Behold, the Savior is said to be a wall.