That the devil has no power against man unless God have allowed it
In the Gospel according to John: “Jesus said, You could have no power against me, unless it were given you from above.” Also in the third of Kings: “And God stirred up Satan against Solomon himself.” Also in Job, first of all God permitted, and then it was allowed to the devil; and in the Gospel, the Lord first permitted, by saying to Judas, “What you do, do quickly.” Also in Solomon, in the Proverbs: “The heart of the king is in God's hand.”
Source: The Treatises of Cyprian (New Advent)