William Burkitt on Acts 26:24

Hitherto Festus had heard the apostle with great patience, but now he interrupts him, and tells him, he talks like a man that was crazed.

Carnal minds pass very uncharitable censures upon spiritual persons and spiritual things. Christ's kindred said, he was beside himself, Mr 3:21. Festus here judged Paul to be mad, thinking that he had over-studied himself: by meddling with matters too high for his capacity, and too deep for his understanding, he had brought himself into a deep melancholy; Paul, thou art beside thyself, much learning hath made thee mad.

But observe with what meekness and due terms of respect the apostle replied to this reviling governor, I am not mad, most noble Festus. Titles of respect and honour, given to persons in place and power, are agreeable to the mind of God, and countenanced by Christianity.

Observe, 2. What an happy victory and conquest the apostle had over his own passions; he waives the reflections Festus had made upon him; and had learned of his master, who, when he was reviled, reviled not again. It is an happy attainment for a man to be master of himself under a provocation, to be regulated by right reason, and not hurried by blind passion.