Albert Barnes Commentary Acts 13:7

"who was with the proconsul, Sergius Paulus, a man of understanding. The same called unto him Barnabas and Saul, and sought to hear the word of God." — Acts 13:7 (ASV)

Which was with the deputy. Or with the proconsul. Cyprus was at this time subject to the Roman Empire and was governed by a proconsul appointed by the emperor. The provinces subject to Rome were governed by persons who held their office originally from the consul, or chief magistrate of the Roman Republic. Men of the rank of senators were usually appointed to these offices.

See Lardner's Credibility, Part I, Chapter 1, § 11 on this subject, where he fully vindicated the accuracy of the designation Luke gives here to Sergius.

Sergius Paulus, a prudent man. The word here rendered prudent means intelligent, wise, learned. It also may have the sense of candid, and he may have been described this way because he held large and liberal views, had a philosophic and inquiring turn of mind, and was willing to obtain knowledge from any source. For this reason, he had entertained the Jews; and for this reason also, he was willing to listen to Barnabas and Saul. It is not often that men in office and men of rank are thus willing to listen to the instructions of the professed ministers of God.

Who called for Barnabas and Saul. It is probable that they had preached in Paphos, and Sergius himself wished to hear the meaning of their new doctrine.

And desired to hear, etc. There is no evidence that he then wished to listen to this as Divine truth, or that he was anxious about his own salvation, but rather as a speculative inquiry. It was a professed characteristic of many ancient philosophers to be willing to receive instruction from any quarter. .