Acts 12:10

When they were past the first and the second ward i.e. the warders, who were stationed one nearer to the inner door of the prison and another at some further distance away.

they came unto the iron gate that leadeth unto[into] the city This description, with the words which immediately follow about the street into which they came, make it probable that the prison in which Peter was kept was in the midst of the city.

which opened to them of his own accord It is better to discard in sentences like the present the old English form "his" and read "its." "His" was good and almost the only English use when the A. V. was made, but is now obsolete.

For the expression "of its own accord" cp. Leviticus 25:5, "That which groweth of its own accord;" Wis 17:6, "A fire kindled of itself," where, as here, what is meant is that there was no human agency employed in what was done.

the angel departed from him Leaving the other steps, in which supernatural aid was unnecessary, to be taken by the Apostle of himself.