Acts 12:4-6

After he had arrested him, he also put him in prison, handing him over to four squads of soldiers to guard him, intending to bring him out for public trial after the Passover. Thus Peter was kept in the prison, but prayer was fervently being made to God by the church for him. Now when Herod was about to bring him out, on that very night Peter was sleeping between two soldiers, bound with two chains, and guards before the door were watching the prison.