Acts 12:1-11 NRSV
About that time King Herod laid violent hands upon some who belonged to the church. He had James, the brother of John, killed with the sword. After he saw that it pleased the Jews, he proceeded to arrest Peter also. (This was during the festival of Unleavened Bread.) When he had seized him, he put him in prison and handed him over to four squads of soldiers to guard him, intending to bring him out to the people after the Passover. While Peter was kept in prison, the church prayed fervently to God for him.
The very night before Herod was going to bring him out, Peter, bound with two chains, was sleeping between two soldiers, while guards in front of the door were keeping watch over the prison. Suddenly an angel of the Lord appeared and a light shone in the cell. He tapped Peter on the side and woke him, saying, “Get up quickly.” And the chains fell off his wrists. The angel said to him, “Fasten your belt and put on your sandals.” He did so. Then he said to him, “Wrap your cloak around you and follow me.” Peter went out and followed him; he did not realize that what was happening with the angel's help was real; he thought he was seeing a vision. After they had passed the first and the second guard, they came before the iron gate leading into the city. It opened for them of its own accord, and they went outside and walked along a lane, when suddenly the angel left him. Then Peter came to himself and said, “Now I am sure that the Lord has sent his angel and rescued me from the hands of Herod and from all that the Jewish people were expecting.”
NRSV: New Revised Standard Version