John Calvin Commentary Acts 24:27

"But when two years were fulfilled, Felix was succeeded by Porcius Festus; and desiring to gain favor with the Jews, Felix left Paul in bonds." — Acts 24:27 (ASV)

And when two years were expired. Since Paul knew that the judge, who was greedy for gain, would be favorable to him as soon as he offered money, and since he had sufficient time to gather it; it is likely that he not only showed forbearance towards the brethren but also detested such bribery, with which the holiness of civil order is shamefully polluted.

Now, while governors usually release prisoners they know are innocent when they leave the province, Felix did the opposite to win favor. The Jews had often complained of his filthy gain, his extortion, cruelty, and misgovernment.

Wearied by so many complaints, Claudius Caesar recalled him from Judea. So that the Jews would not resent him so severely, Felix left Paul bound. In this way, he made the guiltless servant of God, as it were, an offering for his own misdeeds, so that he might thereby appease the priests.