Acts 12: 12a -15 (NIV)
12a he went to the house of Mary the mother of John, also called Mark, where many people had gathered and were praying.
13 Peter knocked at the outer entrance, and a servant named Rhoda came to answer the door.
14 When she recognized Peter’s voice, she was so overjoyed she ran back without opening it and exclaimed, “Peter is at the door!”
15 “You’re out of your mind,” they told her. When she kept insisting that it was so, they said, “It must be his angel.”