Matthew 5:38-40.
“You have heard that it has been said, An eye for an eye, and a tooth for a tooth. But I say unto you, that you resist not the evil: but whosoever shall smite you on the right cheek, turn to him the other also. And if any man will sue you at the law, and take away your coat, let him have your cloak also.”
Do you see that it was not of an eye that He was speaking before, when He made the law to pluck out the offending eye, but of him who by his friendship is harming us, and casting us into the gulf of destruction? For He who in this place uses so great strength of expression, and who, not even when another is plucking out your eye, permits you to strike out his; how should He have made it a law to strike out one's own?
But if any one accuses the ancient law, because it commands such retaliation, he seems to me very unskillful in the wisdom that becomes a legislator, and ignorant of the virtue of opportunities, and the gain of condescension. For if he considered who were the hearers of these sayings, and how they were disposed, and when they received this code of laws, he will thoroughly admit the wisdom of the Lawgiver, and will see that it is one and the same, who made both those laws and these, and who wrote each of them exceeding profitably, and in its due season. Yes, for if at the beginning He had introduced these high and most weighty commandments, men would not have received either these, or the others; but now ordaining them severally in their due time, He has by the two corrected the whole world.
And besides, He commanded this, not that we might strike out one another's eyes, but that we might keep our hands to ourselves. For the threat of suffering has effectually restrained our inclination to be doing.
And thus in fact He is silently dropping seed of much self-restraint, at least in that He commands to retaliate with just the same acts. Yet surely he that began such transgression were worthy of a greater punishment, and this the abstract nature of justice demands. But forasmuch as He was minded to mingle mercy also with justice, He condemns him whose offenses were very great to a punishment less than his desert: teaching us even while we suffer to show forth great consideration.
Having therefore mentioned the ancient law, and recognized it all, He signifies again, that it is not our brother who has done these deeds, but the evil one. For this cause he has also subjoined, “But I say unto you, that you resist not the evil one.” He did not say, “resist not your brother,” but “the evil one,” signifying that on his motion men dare so to act; and in this way relaxing and secretly removing most of our anger against the aggressor, by transferring the blame to another.
“What then?” it is said, “ought we not to resist the evil one?” Indeed we ought, but not in this way, but as He has commanded, by giving one's self up to suffer wrongfully; for thus shall you prevail over him. For one fire is not quenched by another, but fire by water. And to show you that even under the old law he that suffered rather prevails, that he it is who wins the crown; examine just what is done, and you will see that his advantage is great. For as he that has begun with unjust acts, will have himself destroyed the eyes of both, his neighbor's and his own (wherefore also he is justly hated of all, and ten thousand accusations are aimed at him): so he that has been injured, even after his equal retaliation, will have done nothing horrible. Wherefore also he has many to sympathize with him, as being clear from that offense even after he has retaliated. And though the calamity be equal to both parties, yet the sentence passed on it is not equal, either with God, or with men. It should seem then, that neither is the calamity equal in the end.
Now whereas at the beginning He said, “he that is angry with his brother without a cause,” and “he that calls him fool shall be in danger of hell fire,” here He requires yet more entire self-restraint, commanding him that suffers ill not merely to be quiet, but even to be more exceedingly earnest in his turn, by offering the other cheek.
And this He says, not as legislating about such a blow as this only, but as teaching also what forbearance we should practise in all our other trials. For just as when He says, “whoso calls his brother fool, is in danger of hell,” He speaks not of this word only, but also of all reviling; even so here also He is making a law, not so much for our bearing it manfully, when smitten, as that we should be undisturbed, whatever we suffer. Because of this He both there singled out the extremest insult, and here has set down that which seems to be of all blows most opprobrious, the blow on the cheek, so full of all insolence. And He commands this as having regard both of him that strikes and of him that is stricken. Since both he that is insulted will not think that he suffers any harm, being thus framed to self-restraint (nay, he will not even have any sense of the insult, as striving rather for a prize than as receiving a blow); and he that is offering the affront will be made ashamed, and not add a second blow, though he be fiercer than any wild beast, yea, rather will condemn himself heartily for the former. For nothing so restrains the wrong doers, as when the injured bear what is done with gentleness. And it not only restrains them from rushing onward, but works upon them also to repent for what has gone before, and in wonder at such forbearance to draw back. And it makes them more our own, and causes them to be slaves, not merely friends, instead of haters and enemies; even as avenging one's self does just the contrary: for it both disgraces each of the two, and makes them worse, and their anger it heightens into a greater flame; yea, often no less than death itself is the end of it, going on from bad to worse. Wherefore He not only forbade you to be angry when smitten, but even enjoined you to satiate the other's desire, that so neither may the former blow appear to have befallen you against your will. For thus, lost as he may be to shame, you will be able to smite him with a mortal blow, rather than if you had smitten him with your hand; or if his shamelessness be still greater, you will make him gentle in proportion.
Source: Homilies on the Gospel of St. Matthew (New Advent)