Then Saul, (who also is called Paul,) filled with the Holy Ghost, set his eyes on him,
Then Saul, (who also is [called] Paul) - and henceforward Paul only. The practice of giving second names, which sometimes absorbed the first, is of old standing. Many explanations have been given of the change in this case from Saul to Paul. Jerome's one (adopted by Augustine and several modern critics) - that it was designed to commemorate the conversion of the proconsul, whose surname was Paulus-seems to us a poor one; nor does the historian mention the change in connection with this, but rather with the withering address to Elymas. That it was intended (as Bengel and others think) as an allusion to his insignificance of stature and appearance (2 Corinthians 10:1) - the word signifying 'little'-is, in our judgment, not probable. The most natural explanation seems to be, that by this slight change in the first letter of the name, it was not only converted from a Hebrew to a Roman name, and a quite common one, but rendered smoother-though the coincidence between the sense of the word and his personal appearance would occur to most people.
Filled with the Holy Ghost - the spirit of inspiration coming mightily upon him,
Set his eyes on him. (Our English version properly omits the 'and' before this clause, which is not well attested.) It has been remarked that our historian, both in his Gospel and in the Acts, is given to noticing the attitude in which anything of striking interest was said or done.