Then Saul, (who also is called Paul,) filled with the Holy Ghost, set his eyes on him.

People's New Testament

13:9 But Saul, (who also is called Paul). From this date he is the chief figure of the Acts. Barnabas, who had hitherto been the leader, falls behind. The origin of the name Paul is unknown. It is a Roman name, that of a great Roman family, and it is likely that the great apostle had two names, one Jewish, the other Gentile, a common thing anciently. Peter (Mt 16:16), Daniel (Da 1:7), Esther (Es 2:7), and many others afford examples.

Filled with the Holy Ghost. Acting under the impulse of the Holy Spirit.

Wesley's Notes

13:9 Then Saul, who was also called Paul - It is not improbable, that coming now among the Romans, they would naturally adapt his name to their own language, and so called him Paul instead of Saul. Perhaps the family of the proconsul might be the first who addressed to or spoke of him by this name. And from this time, being the apostle of the Gentiles, he himself used the name which was more familiar to them.

Jamieson-Fausset-Brown Bible Commentary

9. Then Saul . also . called Paul-and henceforward Paul only; a softening of his former name, in accommodation to Roman ears, and (as the word signifies "little") probably with allusion as elsewhere to his insignificance of stature and appearance (2Co 10:1, 10) [Webster and Wilkinson].

filled with the Holy Ghost-the Spirit coming mightily upon him.

set his eyes on him and said-Henceforward Barnabas sinks into the background. The whole soul of his great colleague, now drawn out, as never before, shoots, by the lightning gaze of his eye, through the dark and tortuous spirit of the sorcerer. What a picture!

Matthew Henry's Concise Commentary

13:4-13 Satan is in a special manner busy with great men and men in power, to keep them from being religious, for their example will influence many. Saul is here for the first time called Paul, and never after Saul. Saul was his name as he was a Hebrew; Paul was his name as he was a citizen of Rome. Under the direct influence of the Holy Ghost, he gave Elymas his true character, but not in passion. A fulness of deceit and mischief together, make a man indeed a child of the devil. And those who are enemies to the doctrine of Jesus, are enemies to all righteousness; for in it all righteousness is fulfilled. The ways of the Lord Jesus are the only right ways to heaven and happiness. There are many who not only wander from these ways themselves, but set others against these ways. They commonly are so hardened, that they will not cease to do evil. The proconsul was astonished at the force of the doctrine upon his own heart and conscience, and at the power of God by which it was confirmed. The doctrine of Christ astonishes; and the more we know of it, the more reason we shall see to wonder at it. Those who put their hand to the plough and look back, are not fit for the kingdom of God. Those who are not prepared to face opposition, and to endure hardship, are not fitted for the work of the ministry.