Acts 28:31

with all confidence, no man forbidding him--enjoying, in the uninterrupted exercise of his ministry, all the liberty of a guarded man. Thus closes this most precious monument of the beginnings of the Christian Church in its march from east to west, among the Jews first, whose center was Jerusalem; next among the Gentiles, with Antioch for its headquarters; finally, its banner is seen waving over imperial Rome, foretokening its universal triumphs. That distinguished apostle whose conversion, labors, and sufferings for "the faith which once he destroyed" occupy more than half of this History, it leaves a prisoner, unheard, so far as appears, for two years. His accusers, whose presence was indispensable, would have to await the return of spring before starting for the capital, and might not reach it for many months; nor, even when there, would they be so sanguine of success--after Felix, Festus, and Agrippa had all pronounced him innocent--as to be impatient of delay. And if witnesses were required to prove the charge advanced by Tertullus, that he was "a mover of sedition among all the Jews throughout the [Roman] world" (Act 24:5), they must have seen that unless considerable time was allowed them the case would certainly break down. If to this be added the capricious delays which the emperor himself might interpose, and the practice of Nero to hear but one charge at a time, it will not seem strange that the historian should have no proceedings in the case to record for two years.

— Jamieson-Fausset-Brown Commentary (public domain)