Christ was clearly talking about literal weapons. But He was not encouraging His disciples to defend themselves through violence, which would have contradicted His previous instruction, in Matthew 5:38-39, against harming others.

In Luke 9:56, He had stated, “For the Son of man is not come to destroy men’s lives, but to save them.” In Matthew 5:44, He had instructed, “…Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you.”

In Luke 22:37, Christ showed the meaning of His statement: “For I say unto you, that this that is written must yet be accomplished in Me, And He was reckoned among the transgressors: for the things concerning Me have an end [they will be fulfilled].”

Why did Christ instruct His disciples to get swords? To assure the fulfillment of the prophecy in Isaiah 53:12 (which He had inspired and now quoted). He was to be considered a lawbreaker (“transgressor”). He was not endorsing the use of weapons for the purpose of harming other people (whether in self-defense or otherwise). In verse 51 of Luke 22, we see that when Peter drew a sword and strike the High Priest’s servant, Christ chastised him for his actions. He then healed the man by re-attaching his ear, which Peter had cut off.