John Calvin Commentary Acts 25:26

"Of whom I have no certain thing to write unto my lord. Wherefore I have brought him forth before you, and specially before thee, king Agrippa, that, after examination had, I may have somewhat to write." — Acts 25:26 (ASV)

After the examination had taken place. We cannot tell whether the governor, in acquitting Paul before them, seeks by this policy to entice him to drop his appeal. For it was credible that he might easily be persuaded to put aside fear and to submit himself to the judgment and discretion of a just judge, especially if Agrippa should give his friendly consent.

Whatever his purpose in doing it, he condemns himself of iniquity by his own words, because he did not let a guiltless man go free whom he is now ashamed to send to Caesar, having nothing to charge him with. This also came to pass by the wonderful providence of God, so that the Jews themselves would give a prior judgment in Paul’s favor.

Perhaps the governor is proceeding subtly, so that he might discern what the king and the chief men of Caesarea think. His aim might be that if it should happen that Paul is set at liberty, he might lay the blame on them. For he would not want the priests to be his enemies without reason, since a good part of Jerusalem depended on them, and that was the best strategy he could employ when writing to Caesar: to intermingle Agrippa's authority.

But the Lord (to whom it belongs to govern events contrary to human expectation) had another purpose: namely, that when the clouds of false accusations were dispersed, Paul might more freely declare sound doctrine.