John Calvin Commentary Acts 9:13

"But Ananias answered, Lord, I have heard from many of this man, how much evil he did to thy saints at Jerusalem:" — Acts 9:13 (ASV)

Lord, I have heard. In objecting to the danger before the Lord, Ananias reveals his weakness of faith. Therefore, we see that the saints and servants of God are afraid of death, a fear that keeps them back from doing their duty; indeed, it sometimes causes them to stagger.

Ananias would gladly go somewhere else. However, it is a mark of a good man that he does not yield so much to fear that he withdraws himself from Christ’s obedience.

And therefore, this is a sign of rare obedience: although he was somewhat hesitant at first due to the fear of death, yet soon, having put himself aside, he makes great haste to go where Christ called him.

And yet, despite this, he does not flatly refuse in these words to do what he is commanded, but offers an excuse very modestly: "Lord, what does this mean, that you are sending me to the hangman?" Therefore, we can see a desire to obey mixed with fear.