John Calvin Commentary Acts 12:11

"And when Peter was come to himself, he said, Now I know of a truth, that the Lord hath sent forth his angel and delivered me out of the hand of Herod, and from all the expectation of the people of the Jews." — Acts 12:11 (ASV)

Then Peter returning to himself. This is, word for word, "being made in himself," because, having been previously astonished by a strange and incredible event, he was, so to speak, beside himself. But now at last, as if after a trance, he knows that he has been delivered from death.

His words recorded by Luke contain a thanksgiving, for he extols in his heart the benefit of God which he had experienced and tasted. He highly commends it in his heart until he finds other witnesses. He says that the angel was sent by God, according to the common understanding of the godly, who believe that angels are appointed as ministers to care for and take charge of their safety. For unless he had been persuaded of this, he would not have spoken of the angel.

And yet he does not commend the angel as the author of this grace, but he ascribes all the praise for the work to God alone. Nor do angels help us for the purpose of taking for themselves even the least jot of God’s glory. When he says that he was delivered out of the hand of Herod, he magnifies the goodness and benefit of God by the power of his enemy.

What he adds concerning the Jews serves the same purpose. For the greater the number of enemies, the more excellent was God's grace toward His servant. Indeed, it is a great matter that when God alone is favorable, the deadly hatred of the entire world should come to nothing.