So the word of the Lord continued to increase and prevail mightily.
20. Grew mightily [lions.] The word κατα κρατος doth signify that the word increased not a little, (or that these proceedings were not common) as if he should say, that in those increasings appeared rare efficacy, and such as was greater than it used commonly to be.
The preachers of the gospel were sent forth to carry on a war against Satan, and therein Christ went forth conquering and to conquer. The casting of evil spirits out of those that were possessed was one instance of Christ's victory over Satan; but, to show in how many ways Christ triumphed over that great enemy, we have here in these verses two remarkable instances...
Commenting on Acts 19:13-20
And the same time there arose no small stir about that way. The Syriac version reads, "the way of God"; and the Vulgate Latin version, "the way of the Lord": that is, the Christian religion, and the doctrines and ordinances of the Gospel, which the saints were directed to walk in; and the Ethiopic version renders it, "about this doctrine"; which mightily grew and prevailed...