John Calvin on Acts 22:4-5

4. I persecuted this way. This is the second point, that he was an enemy to Christ’s doctrine, and that he was more fervent in resisting the same than all the rest, until he was pulled back by the hand of God; which thing he saith the chief priests and elders can testify. Therefore, there can be no suspicion in such a sudden change. Whereas he saith, that he had letters given him to deliver to the brethren, it must be referred unto the Jews, as if he had called them his countrymen; but he meant to appease them with a more honorable title. For this is Paul’s drift, that he may declare his natural and lawful beginning which he took of that nation; “Ab ilia genta... originem,” origin from that nation. and also how desirous he was to be linked with them in friendship.

Acts 22:6-11

6. And it happened that as I journeyed and drew near to Damascus about noon, that suddenly a great light shone round about me from heaven. 7. And I fell to the ground, and heard a voice saying to me, Saul, Saul, why persecutest thou me? 8. And I answered, Who art thou, Lord? And he said to me, I am Jesus of Nazareth, whom thou persecutest. 9. And they which were with me saw indeed the light, and were afraid: but they heard not the voice of him which talked with me. 10. Then I said, What shall I do, Lord? And the Lord said to me, Arise, and go to Damascus; and there it shall be told thee what things be ordained for thee to do. 11. And when I saw not by reason of the glory of the light, being led by the hand by those companions which were with me, I came to Damascus.