Acts of the Apostles 12:1-11.
In those days, King Herod laid hands upon some members of the Church to harm them.
He had James, the brother of John, killed by the sword,
and when he saw that this was pleasing to the Jews he proceeded to arrest Peter also. (It was (the) feast of Unleavened Bread.)
He had him taken into custody and put in prison under the guard of four squads of four soldiers each. He intended to bring him before the people after Passover.
Peter thus was being kept in prison, but prayer by the church was fervently being made to God on his behalf.
On the very night before Herod was to bring him to trial, Peter, secured by double chains, was sleeping between two soldiers, while outside the door guards kept watch on the prison.
Suddenly the angel of the Lord stood by him and a light shone in the cell. He tapped Peter on the side and awakened him, saying, “Get up quickly.” The chains fell from his wrists.
The angel said to him, “Put on your belt and your sandals.” He did so. Then he said to him, “Put on your cloak and follow me.”
So he followed him out, not realizing that what was happening through the angel was real; he thought he was seeing a vision.
They passed the first guard, then the second, and came to the iron gate leading out to the city, which opened for them by itself. They emerged and made their way down an alley, and suddenly the angel left him.
Then Peter recovered his senses and said, “Now I know for certain that (the) Lord sent his angel and rescued me from the hand of Herod and from all that the Jewish people had been expecting.”