Luke 22:36 is often debated and used as a proof-text in arguments over pacifism. In the following post I will read it in context, and show that major traditional understandings are flawed, and that the verse is not a simple deal-breaker for a Christian pacifism.
The context of the passage is set up by the whole narrative thread, picking up from the start of the chapter: the decision of Judas to betray Jesus, the Last Supper, and the prediction of Peter's Betrayal in v31-34. In Luke 22:35 Jesus asks them:
And he said to them, “When I sent you out with no moneybag or knapsack or sandals, did you lack anything?”
They said, “Nothing.”
Referring back to Luke 9:3. In that former context, Jesus sent them out on a missionary journey to Israelites, with the expectation that those who received them would show due hospitality, so that there was no need for provisioning. There is no mention of a sword in the Luke 9:1-5 context. The response of the disciples here points to the provision of God, and Jesus' question functions didactically to remind them of a previously learnt lesson. We then come to the difficult verse, Luke 22:36:
He said to them, “But now let the one who has a moneybag take it, and likewise a knapsack. And let the one who has no sword sell his cloak and buy one.
Jesus echoes his former instruction, but reverses its direction. Now there will be a need for provisioning. Why is that? I suggest that the need for provisions here is the consequence of the change in hospitality that is about to ensue - no longer will their missionary activity be received by faithful Israelites awaiting a Messiah. The disciples from this point on will experience a hostility patterned on Jesus' own experience.
In this context, the command concerning the sword (it is framed as a 3rd person imperative, which to some extent distances it from the immediate context), has been read in a number of ways. Some have seen it as an instruction to arm themselves for future self-defence, a sword being a standard protection from robbers. Others have read it metaphorically, as spiritual armament for 'battle'. Neither of these is adequate to the ongoing context. While it is true that most of the NT, especially the Pauline material, uses military language metaphorically, it is difficult to read the sword here as metaphorical, given the literal nature of the rest of the command. Luke 22:37-38:
For I tell you that this Scripture must be fulfilled in me:
‘And he was numbered with the transgressors.’
For what is written about me has its fulfillment.”
38And they said, “Look, Lord, here are two swords.”
And he said to them, “It is enough.”
Jesus continues his instructions with an explicit reference to Isa 53:12. The disciples do not respond to this, but instead reply to his very practical statement in v36, with "Here are two swords". The clear implication is that the disciples are already in possession of two swords, and probably have been for some time. Now, everything about this passage so far turns on how we read Jesus' reply, "It is enough."
Enough for what? To go back to our comments on v35, it is very difficult to see how two swords will be sufficient for anything - it isn't sufficient in the arrest scene to ward off that band. It's hardly sufficient for traveling bands of apostolic missionaries (especially if they followed a Luke 9 two by two pattern), to ward off robbers. The sufficiency of two swords is ironic, and must be read against two other texts. Firstly, the immediate context of v37 provides the sufficiency of which Jesus speaks. Two swords are enough to fulfil the scripture, "with the lawless he was reckoned" (my translation; lawless is a plural substantive). When you read Luke 22:52, and Jesus asks if they have come out as against a robber, the implied answer is 'Yes', because that is how the band of temple-officers and their chiefs is portrayed, and the armament of Jesus' companions, and their violence in Lk 22:49-51 fulfils this very scripture.
Secondly, Jesus' words "It is enough" function as a summary rebuke, as "Enough!" might in English. The disciples haven't got the import of what Jesus has said, though ironically they will fulfil that scripture, and Jesus' wording alludes to Dt 3:26 LXX, where God angrily breaks off from speaking to Moses.
The flow of the narrative from this point on continues to reinforce this understanding. Jesus offers no resistance, though he of anyone is supremely qualified to legitimate self-defence. His disciple does not wait for the answer of Lk 22:49, "shall we strike?", but strikes immediately. Jesus' response is again a summary rebuke, "No more of this!" (Lk 22:51), and heals the high-priest's slave's ear, reversing the violence done.
Why don't the disciples act differently? I surmise, that as with most of Jesus' teachings, the disciples fail to grasp the implications of Jesus' words until post-resurrection. It is only then they understand the shape of Jesus' life as cross-directed, and will begin to understand that to follow Jesus is likewise to surrender self-determination and take up one's cross. That will include an entire re-evaluation of the meaning of death, and thus the sufficiency of the sword.
There is a further line of interpretation that I have not explored here. Yoder picks it up marvellously in The Politics of Jesus. That is that the real temptation and choice of "Remove this cup from me" (Lk 22:42), is the choice between atoning sacrifice and forgiveness, against messianic violence and the consummation of the Kingdom with divine judgment. The choice of the disciples to engage in armed insurrection literalises that choice in historical reality, but it is the very choice that Jesus rejects.