John Calvin Commentary John 18:10

"Simon Peter therefore having a sword drew it, and struck the high priest`s servant, and cut off his right ear. Now the servant`s name was Malchus." — John 18:10 (ASV)

Then Simon Peter, having a sword, drew it. The Evangelist now describes the foolish zeal of Peter, who attempted to defend his Master in an unlawful manner. Indeed, he boldly and courageously incurs great risk on Christ's account; but because he does not consider what his calling demands and what God permits, his action is so far from deserving praise that he is severely blamed by Christ.

But let us learn from this that, in the person of Peter, Christ condemns everything that people dare to attempt out of their own imagination. This doctrine is highly worthy of attention, for nothing is more common than to defend everything we do under the cloak of zeal, as if it were of no importance whether God approved or not what people suppose to be right, whose prudence is nothing but mere vanity.

Even if we saw nothing faulty in the zeal of Peter, we still ought to be satisfied on this single ground: that Christ declares He is displeased with it. But we see that it was not due to him that Christ did not turn aside from death, and that His name was not exposed to perpetual disgrace. For, in offering violence to the captain and the soldiers, he acts like a highwayman, because he resists the power that God has appointed. Since Christ was already hated more than enough by the world, this single deed might have given plausibility to all the slanders His enemies falsely brought against Him.

Besides, it was exceedingly thoughtless of Peter to attempt to prove his faith by his sword, while he could not do so by his tongue. When he is called to make a confession, he denies his Master; and now, without his Master’s authority, he causes a disturbance.

Warned by such a striking example, let us learn to keep our zeal within proper bounds. Since the unruliness of our flesh is always eager to attempt more than God commands, let us learn that our zeal will turn out badly whenever we venture to undertake anything contrary to the word of God. It will sometimes happen that the beginning gives us flattering promises, but we will in the end be punished for our rashness.

Therefore, let obedience be the foundation of all that we undertake. We are also reminded that those who have resolved to plead the cause of Christ do not always conduct themselves so skillfully as not to commit some fault; and therefore, we ought all the more earnestly to implore the Lord to guide us in every action by the spirit of prudence.