“And when he had considered the thing, he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying.”
King James Version (KJV)
12:12 And having considered - What was best to be done. Many were gathered together - At midnight.
Ac 12:12 Came to the house of Mary. This Mary was the mother of Mark, called in Acts both John and Mark. See Ac 13:5,13 15:39. She was related to Barnabas (Col 4:10). Many were assembled together praying. For Peter's deliverance.