ACT 12:4

4 After [they] seized Peter, they put him in prison. They arranged for four groups of soldiers to guard Peter. Each [group] had four soldiers. [Every three hours a different group began to guard him while the others rested]. Herod wanted to bring Peter out [of prison and judge him] in front of the [Jewish] people after the Passover [Festival was finished. He then planned to command soldiers to execute Peter].