Acts 16:9 - Coke's Commentary on the Holy Bible

There stood a man of Macedonia,— Some think St. Paul knew his country by his dress, or language; but there was no need of his attending to such particularities, as the vision itself mentions the country: it has also been thought, by some, to have been a particular person with whom St. Paul was acquainted in Macedonia, and therefore they would render the Greek literally a certain Macedonian. Grotius has suggested that it was the guardian angel of Macedonia, who appeared in human form. See his note on the place.