Acts 12:3-5

³and, when he saw that the Jews were pleased with this, he proceeded to arrest Peter also. (This was during the Festival of the unleavened bread.)

⁴After seizing Peter, Herod put him in prison, and entrusted him to the keeping of four Guards of four soldiers each, intending, after the Passover, to bring him up before the people.

⁵So Peter was kept in prison, but meanwhile the prayers of the church were being earnestly offered to God on his behalf.