John Calvin Commentary Matthew 12:28

"But if I by the Spirit of God cast out demons, then is the kingdom of God come upon you." — Matthew 12:28 (ASV)

But if I cast out devils by the Spirit of God. Luke says, if I cast out devils by The Finger of God; employing the word Finger metaphorically instead of the Spirit. As God works and exerts his power by his Spirit, it is appropriate that the word Finger is applied to him.

And this mode of expression was common among the Jews, as Moses relates that Pharaoh’s magicians said, This is the finger of God.

Now Christ infers from what he has already stated that the scribes prove themselves to be ungrateful to God by being unwilling that He should reign among them. Until now, he replied to their idle slander; but now, he treats them as convicted persons and charges them not to make ungodly opposition to the kingdom of God.

He does not confine himself to a single miracle but takes occasion from it to speak about the object of his coming. He reminds them that they ought not merely to look at one remarkable fact, but at a far more important truth: that it was the will of God, by revealing His Messiah, to raise up their salvation which was fallen, and to restore his kingdom among them.

Thus we see that Christ complains of their ingratitude in madly rejecting from their midst the inestimable grace of God.

The kingdom of God has come to you. The word come is emphatic and implies that, without any request from them, God appears as their Redeemer, while they do everything in their power to drive him away and, when he is present and prepared for their salvation, refuse to give him a place.