“When they were past the first and the second ward, they came unto the iron gate that leadeth unto the city; which opened to them of his own accord: and they went out, and passed on through one street; and forthwith the angel departed from him.”
King James Version (KJV)
12:10 The first and second ward - At each of which doubtless was a guard of soldiers. The gate opened of its own accord - Without either Peter or the angel touching it. And they went on through one street - That Peter might know which way to go. And the angel departed from him - Being himself sufficient for what remained to be done.
Ac 12:10 The first and second ward. Watches. The soldiers on watch seem to have been stationed apart, one near Peter's door, the other near the gate. The iron gate. The outer gate of the prison. It was after it was passed, and the angel had left him in the street, that Peter was first sure that it was no vision, but that the Lord had delivered him.