Matthew Henry on Acts 12:1-5

James was one of the sons of Zebedee, whom Christ told that they should drink of the cup that he was to drink of, and be baptized with the baptism that he was to be baptized with, Mt 20:23. Now the words of Christ were made good in him; and if we suffer with Christ, we shall reign with him. Herod imprisoned Peter: the way of persecution, as of other sins, is downhill; when men are in it, they cannot easily stop. Those make themselves an easy prey to Satan, who make it their business to please men. Thus James finished his course. But Peter, being designed for further services, was safe; though he seemed now marked out for a speedy sacrifice. We that live in a cold, prayerless generation, can hardly form an idea of the earnestness of these holy men of old. But if the Lord should bring on the church an awful persecution like this of Herod, the faithful in Christ would learn what soul-felt prayer is.