Albert Barnes Commentary Acts 25:9

"But Festus, desiring to gain favor with the Jews, answered Paul and said, Wilt thou go up to Jerusalem, and there be judged of these things before me?" — Acts 25:9 (ASV)

But Festus, willing to do the Jews a pleasure. He was desirous of securing their favor, as he had just entered on his administration . In this, he showed rather a desire for popularity than an inclination to do justice. Had he been disposed to do right at once, he would have immediately discharged Paul.

Festus perceived that the case was one that did not come fairly within the jurisdiction of a Roman magistrate; that it pertained solely to the customs and questions among the Jews (Acts 25:18–20), and he therefore proposed that the case should be tried before him at Jerusalem. It is remarkable, however, that he had such a sense of justice, and law, as not to allow the case to go out of his own hands.

He still proposed to hear the case, but asked Paul whether he was willing that it should be tried at Jerusalem. Since the question he asked Paul was one on which Paul was at liberty to take his own course, and since Paul had no reason to expect that his going to Jerusalem would facilitate the cause of justice, it is not remarkable that he declined the offer, as Festus perhaps supposed he would.