Adam Clarke on Acts 13:7

The deputy of the country - Ανθυπατῳ, The proconsul. Rosenmuller and others remark, that in those days the Romans sent two different kinds of governors into the provinces. Some of the provinces were Caesarean or imperial, and into those they sent propretors; others belonged to the senate and people of Rome, and into those they sent proconsuls. Cyprus had formerly been an imperial province; but Augustus, who made the distinction, had given it to the people, whence it was governed by a proconsul. See Dion Cass. Hist. Rom. lib. iv. p. 523. (Edit. Leunclav.)

Sergius Paulus - This proconsul is not mentioned any where else: he became a Christian, had his name written in the book of life, and, probably on that very account, blotted out of the Fasti Consulares.

A prudent man - Ανδρι συνετῳ, A man of good sense, of a sound understanding, and therefore wished to hear the doctrine taught by these apostles; he did not persecute the men for their preaching, but sent for them that he might hear for himself.