John Calvin on Acts 9:12

12. He saw a man, named Ananias. It is uncertain whether Luke do yet repeat the words of Christ, or he add this of his own. Those which take it in the person of Luke are moved with some show of absurdity, because it is an unlikely thing that Christ used these words. Although this may be easily answered thus, to wit, that Christ confirmeth Ananias after this sort, There is no cause why thou shouldst fear but that he will receive thee willingly, forasmuch as he already knoweth thy shape by a vision. I have also told him thy name, and whatsoever thou shalt do with him. Yet may the reader choose whether he will.

Acts 9:13-16

13. And Ananias answered, Lord, I have heard of many of this man, what hurt he hath done to thy servants at Jerusalem: 14. And here he hath power from the priests to bind all which call upon thy name. 15. And the Lord said unto him, Go; because he is a chosen instrument to me to bear my name before the Gentiles, and kings, and the children of Israel. 16. For I will show him how great things he must suffer for my name.