And a certain Jew named Apollos - Apollos afterward became a distinguished and successful preacher of the gospel, 1Co 1:12; 1 Corinthians 3:5-6; 1 Corinthians 4:6; Titus 3:13. Nothing more is known of him than is stated in these passages.
Born at Alexandria - Alexandria was a celebrated city in Egypt, founded by Alexander the Great. There were large numbers of Jews resident there. See the notes on Acts 6:9.
An eloquent man - Alexandria was famous for its schools, and it is probable that Apollos, in addition to his natural endowments, had enjoyed the benefit of these schools.
Mighty in the scriptures - Well instructed, or able in the Old Testament. The foundation was thus laid for future usefulness in the Christian church. See the notes on Luke 24:19.