Matthew 22:13

He who has thus insulted the marriage feast is not only cast out therefrom, but besides by the King's officers, who are set over his prisons, is chained up from that power of walking which he employed not to walk to any good thing, and that power of reaching forth his hand, wherewith he had fulfilled no work for any good; and is sentenced to a place whence all light is banished, which is called outer darkness.

Seest thou how, although the fact was so manifest, He doth not punish at once, until he himself, who has sinned, has passed the sentence? For by having nothing to reply he condemned himself, and so is taken away to the unutterable torments. For do not now, on hearing of darkness, suppose he is punished by this, by sending into a place where there is no light only, but where there is also weeping and gnashing of teeth. And this He saith, indicating the intolerable pains. Hear ye, as many as having partaken of the mysteries, and having been present at the marriage, clothe your souls with filthy deeds. Hear whence ye were called. From the highway. Being what? Lame and halt in soul, which is a much more grievous thing than the mutilation of the body. Reverence the love of Him, who called you, and let no one continue to have filthy garments, but let each of you busy himself about the clothing of your soul. Hear, ye women; hear, ye men; we need not these garments that are bespangled with gold, that adorn our outward parts, but those others, that adorn the inward. Whilst we have these former, it is difficult to put on those latter. It is not possible at the same time to deck both soul and body. It is not possible at the same time both to serve mammon, and to obey Christ as we ought. Let us put off us therefore this grievous tyranny. For neither if any one were to adorn thy house by hanging it with golden curtains, and were to make thee sit there in rags, naked, wouldest thou endure it with meekness. But lo, now thou doest this to thyself, decking the house of thy soul, I mean the body, with curtains beyond number, but leaving the soul itself to sit in rags. Knowest thou not that the king ought to be adorned more than the city? so therefore while for the city hangings are prepared of linen, for the king there is a purple robe and a diadem. Even so do thou wrap the body with a much meaner dress, but the mind do thou clothe in purple, and put a crown on it, and set it on a high and conspicuous chariot. For now thou art doing the opposite, decking the city in various ways, but suffering the king, the mind, to be dragged bound after the brute passions. Rememberest thou not, that thou art bidden to a marriage, and to God's marriage? Considerest thou not how the soul that is bidden ought to enter into those chambers, clad, and decked with fringes of gold.

By a metaphor taken from the body, there shall be weeping and gnashing of teeth, is shown the greatness of the torments. The binding of the hands and feet also, and the weeping of eyes, and the gnashing of teeth, understand as proving the truth of the resurrection of the body.

(de Trin. xi. 6.) The bonds of wicked and depraved desires are the chains which bind him who deserves to be cast out into outer darkness.

Or, it points to the difference of punishment inflicted on sinners. Outer darkness being the deepest, inward darkness the lesser, as it were the outskirts of the place.