When they were past the first and the second ward. — It would seem from this that Peter had been placed in the innermost dungeon, and had to pass the two court-yards. Lightfoot supposes the prison to have been between the inner and outer walls of the city, the direction of Peter’s movements being from the outer to the inner.
The iron gate. — The touch of topographical precision may be noticed as characteristic of St. Luke.
Passed on through one street. — The word implies one of the narrow streets or lanes of the city. (See Note on Matthew 6:2.)