Luke 22:37

He next lays open the cause of these evils, namely, that He suffered the penalty due to the wicked, being crucified with thieves. And when it shall have come at last to this, the word of dispensation will receive its end. But to the persecutors shall happen all that has been foretold by the Prophets.

But He who forbids to strike, why does He order them to buy a sword? unless perchance that there may be a defence prepared, but no necessary retaliation; a seeming ability to be revenged, without the will. Hence it follows, And he who has not, (that is, a purse,) let him sell his garment, and buy a sword. Or, because the law does not forbid to return a blow, perhaps He says to Peter, as he is offering the two swords, It is enough, as though it were lawful until the Gospel; in order that there may be in the law, the knowledge of justice; in the Gospel, perfection of goodness. There is also a spiritual sword, that you may sell your patrimony, and buy the word, by which the nakedness of the soul is clothed. There is also a sword of suffering, so that you may strip your body, and with the spoils of your sacrificed flesh purchase for yourself the sacred crown of martyrdom. Again it moves, seeing that the disciples put forward two swords, whether perhaps one is not of the Old Testament, the other of the New, whereby we are armed against the wiles of the devil. Therefore the Lord says, It is enough, because he wanted nothing who is fortified by the teaching of both Testaments.

What is, this? He who said, If any one strike you on the right cheek, turn unto him the other also, (Matt. 5:39.) now arms His disciples, and with a sword only. For if it were fitting to be completely armed, not only must a man possess a sword, but shield and helmet. But even though a thousand had arms of this kind, how could the eleven be prepared for all the attacks and lying in wait of people, tyrants, allies, and nations, and how should they not quake at the mere sight of armed men, who had been brought up near lakes and rivers? We must not then suppose that He ordered them to possess swords, but by the swords He points at the secret attack of the Jews. And hence it follows, For I say unto you, that this that is written must be accomplished in me: And he was numbered with the transgressors. (Isa. 53:12.)

While they were contending among themselves above concerning priority, He saith, It is not a time of dignities, but rather of danger and slaughter. Behold I even your Master am led to a disgraceful death, to be reckoned with the transgressors. For these things which are prophesied of Me have an end, that is, a fulfilment. Wishing then to hint at a violent attack, He made mention of a sword, not altogether revealing it, lest they should be seized with dismay, nor did He entirely provide that they should not be shaken by these sudden attacks, but that afterwards recovering, they might marvel how He gave Himself up to the Passion, a ransom for the salvation of men. Or He hereby foretels to them that they would incur hunger and thirst, which He implies by the scrip, and sundry kinds of misery, which he intends by the sword. Our Lord then was unwilling to blame them as not understanding Him, but saying, It is enough, He dismissed them; as when we are addressing any one, and see that he does not understand what is said, we say, Well, let us leave him, lest we trouble him. But some say, that our Lord said, It is enough, ironically; as if He said, Since there are two swords, they will amply suffice against so large a multitude as is about to attack us.