Luke 11:20

But if I by the finger of God cast out demons, then is the kingdom of God come upon you.

The finger of God ... This was a master stroke. When Moses performed great wonders before Pharaoh, and when for a time the magicians duplicated the wonders, then came the plague of lice. Aaron stretched the rod upon the land, and the dust of the earth became lice in man and beast (Exodus 8:17). Attempting to do this they failed; and they went and told Pharaoh, "This is the finger of God" (Exodus 8:19). Jesus' use of the same language here stresses the superiority of his miracles over the professed cures performed by the sons of the Pharisees.

Then is the kingdom of God come upon you ... This is not a declaration that Christ's church, or kingdom, had at this time been established, an event that took place on Pentecost. The kingdom had come in the sense that the King had appeared and was gathering out of secular Israel, the spiritual remnant, the true Israel, who, along with Gentiles, would form the nucleus of the new institution. See under Luke 11:4.