John Calvin Commentary Matthew 9:34

"But the Pharisees said, By the prince of the demons casteth he out demons." — Matthew 9:34 (ASV)

But the Pharisees said—from this it is evident with what rage and fury they were filled, who did not hesitate to attack with wicked slander so glorious a work of God.

We should observe the contrast between the applause of the people and the blasphemy of those men. The saying of the people, that nothing like it ever happened in Israel, is a confession arising from a sense of the divine glory, which makes it all the more evident that those individuals were utterly mad who dared, as it were, to curse God to His face.

We also learn from this that when wickedness has reached the height of blindness, there is no work of God, however evident, which it will not pervert.

It is, undoubtedly, monstrous and incredible that mortal men should cry out against their Creator. But there is all the more reason for dreading that blindness, which arises from the Lord’s vengeance on the wicked after long-suffering.