Luke 22:37

For I say unto you, that this which is written must be fulfilled in me, And he was reckoned with transgressors: for that which concerneth me hath fulfillment. And they said, Lord, behold here are two swords. And he said unto them, It is enough.

That which is written must be fulfilled ... The avowed intention of the Pharisees was to kill Jesus by assassination (Matthew 26:1-5); and despite their change of strategy due to the treachery of Judas, many of them doubtless preferred the method of killing Jesus they had already agreed upon; and the view here is that Christ would have ordered the apostles to resist any effort to assassinate him. The sword in view here, therefore, was an assurance that his purpose of witnessing his godhead before the Sanhedrin would not be thwarted by an untimely assassination.

When the time came, of course, Jesus would submit to arrest by lawful authority; and the possession by his apostles of swords, coupled with his prohibition of their use against such lawful authority, emphatically dramatized the willingness of his submission. Barnes' note that "the apostles followed the customs of the country, and had with them some means of defense"[23] is doubtless true.

It is enough ... It is customary to interpret this expression as an assertion that the disciples were missing his point altogether, as if he had said, "Enough of this!" But there is no valid reason for supposing that these words mean anything other than "two swords are enough." As a matter of fact, the swords were a necessary part of the drama of the Lords arrest. Jesus used the excision of Malchus' ear as an occasion to command Peter to put up his sword into "its place," a powerful endorsement of the premise that such a sword of self-defense HAS its place (see my Commentary on Matthew, Matthew 26:52). Significantly, even then, Jesus neither commanded Peter to throw his sword away or surrender it.