Expositor's Bible Commentary Commentary Acts 12:10

"And when they were past the first and the second guard, they came unto the iron gate that leadeth into the city; which opened to them of its own accord: and they went out, and passed on through one street; and straightway the angel departed from him." — Acts 12:10 (ASV)

Passing the two guards at the inner entrance to the prison, Peter and the angel came to the main iron gate, which opened automatically as they approached. Then the angel left Peter a block away from the prison. For Peter, standing there alone in the street and brought to his senses by the cool night air, there was no doubt that “the Lord sent his angel and rescued me [Peter] from Herod’s clutches and from everything the Jewish people were anticipating.”