Acts 12:15

It is his angel - It was a common opinion among the Jews that every man has a guardian angel, and in the popish Church it is an article of faith. The Jews also believed that angels often assumed the likeness of particular persons. They have many stories of the appearance of Elijah in the likeness of different rabbins. As αγγελος signifies in general a messenger, whether Divine or human, some have thought that the angel or messenger here means a servant or person which the disciples supposed was sent from Peter to announce something of importance to the brethren: it was also an opinion among the Jews, even in the time of the apostles, as appears from Philo, that the departed souls of good men officiated as ministering angels; and it is possible that the disciples at Mary's house might suppose that Peter had been murdered in the prison; and that his spirit was now come to announce this event, or give some particular warning to the Church.

Thou art mad - Thou art insane. They seemed to have regarded his rescue as so difficult and so hopeless, that they deemed it proof of derangement that she now affirmed it. And yet this was the very thing for which they had been so earnestly praying. When it was now announced to them that the object of their prayers was granted, they deemed the messenger that announced it insane. Christians are often surprised even when their prayers are answered. They are overwhelmed and amazed at the success of their own petitions, and are slow to believe that the very thing for which they have sought could be granted. It shows, perhaps, with how little faith, after all, they pray, and how slow they are to believe that God can hear and answer prayer. In a revival of religion in answer to prayer, Christians are often overwhelmed and astonished when even their own petitions are granted, and when God manifests his own power in his own way and time. Prayer should be persevered in, and we should place ourselves in a waiting posture to catch the first indications that God has heard us.

But she constantly affirmed - She insisted on it. How much better it would have been to have hastened at once to the gate, than thus to have engaged in a controversy on the subject. Peter was suffered to remain knocking while they debated the matter. Christians are often engaged in some unprofitable controversy when they should hasten to catch the first tokens of divine favor, and open their arms to welcome the proofs that God has heard their prayers.

Then said they - Still resolved not to be convinced.

It is his angel - Any way of accounting for it rather than to admit the simple fact, or to ascertain the simple truth. All this was caused by the little hope which they had of his release, and their earnest desire that it should be so. It was just such a state of mind as is indicated when we say, "The news is too good to e believed." The expression "It is his angel" may mean that they supposed that the "tutelary guardian," or angel appointed to attend Peter, had come to announce something respecting him, and that he had assumed the voice and form of Peter in order to make them certain that he came from him. This notion arose from the common belief of the Jews that each individual had assigned to him, at birth, a celestial spirit, whose office it was to guard and defend him through life. See the notes on Matthew 18:10. That the Jews entertained this opinion is clear from their writings. See Kuinoel. Lightfoot thinks that they who were assembled supposed that the angel had assumed the voice and manner of Peter in order to intimate to them that he was about to die, and to excite them to earnest prayer that he might die with constancy and firmness. Whatever their opinions were, however, it proves nothing on these points. There is no evidence that they were inspired in these opinions, nor are their notions countenanced by the Scriptures. They were the mere common traditions of the Jews, and prove nothing in regard to the truth of the opinion one way or the other.

12:15 They said, Thou art mad - As we say, Sure you are not in your senses to talk so. It is his angel - It was a common opinion among the Jews, that every man had his particular guardian angel, who frequently assumed both his shape and voice. But this is a point on which the Scriptures are silent.