John Calvin Commentary Matthew 26:72

"And again he denied with an oath, I know not the man." — Matthew 26:72 (ASV)

And the second time he denied with an oath. It deserves attention that Peter, after finding that he could not escape by a simple denial, doubles his crime by adding an oath; and a little later, when he is still more vehemently pressed, he proceeds even to cursing.

From this we infer that a sinner, after having once fallen, is always hurried from bad to worse. Those who begin with ordinary offenses afterward rush headlong into the basest crimes, from which at first they would have recoiled with horror.

And this is the just vengeance of God: after we have deprived ourselves of the assistance of the Holy Spirit, He allows Satan to exercise violent power over us, so that Satan, having subdued us and made us his slaves, may drive us wherever he pleases.

This happens chiefly in denying the faith. For when a person, through fear of the cross, has turned aside from a pure profession of the gospel, if he perceives that his enemies are not yet satisfied, he will proceed further; and what he had not ventured to acknowledge fully, he denies flatly with an oath and without any ambiguity of words.

We ought also to observe that almost in a single moment Peter thrice gave way. This shows how unsteady we are and how liable to fall whenever Satan drives us. Certainly, we will never cease to fall if the Lord does not stretch out His hand to uphold us.

When the power of the grace of Christ was extinguished in Peter, whoever might afterward meet him and interrogate him about Christ, he would have been ready to deny a hundred or a thousand times. Although, then, it was very shameful for him to fall thrice, yet the Lord spared him by restraining the tongues of enemies from making additional attacks on him.

Thus, also, it is necessary every day for the Lord to bridle Satan, lest Satan overwhelm us with innumerable temptations. For though Satan does not cease to employ many instruments in assailing us, if the Lord, paying regard to our weakness, did not restrain the violence of Satan's rage, we would have to contend against a prodigious amount of temptations.

In this respect, therefore, we ought to praise the mercy of the Lord, who does not permit our enemy to advance against us even a hundredth part of what Satan would desire.