Acts 12:10

When they were past

(διελθοντες). Second aorist active participle of διερχομα, transitive with δια in composition.The first and the second ward

(πρωτην φυλακην κα δευτεραν). It is not clear to what this language refers. Some take it to mean single soldiers, using φυλακην in the sense of a guard (one before the door, one at the iron gate). But it seems hardly likely that the two soldiers with whom Peter had been stationed are meant. Probably the "first ward" means the two soldiers of the quaternion stationed by the door and the second ward some other soldiers, not part of the sixteen, further on in the prison by the iron gate. However understood, the difficulties of escape are made plain.Unto the iron gate that leadeth into the city

(επ την πυλην την σιδηραν την φερουσαν εις την πολιν). Note the triple use of the article (the gate the iron one the one leading into the city). For this resumptive use of the article see Robertson, Grammar, pp. 762, 764. This iron gate may have opened from a court out into the street and effectually barred escape.Opened to them

(ηνοιγη αυτοις). Second aorist passive indicative of ανοιγω, the usual later form though ηνοιχθη (first aorist passive) occurs also, was opened.Of its own accord

(αυτοματη). Old compound adjective (αυτος, self, obsolete μαω, to desire eagerly, feminine form though masculine αυτοματος also used as feminine). In the N.T. only here and Mark 4:28. It was a strange experience for Peter. The Codex Bezae adds here "went down the seven steps" (κατεβησαν τους επτα βαθμους), an interesting detail that adds to the picture.One street

(ρυμην μιαν). The angel saw Peter through one of the narrow streets and then left him. We have no means of knowing precisely the location of the prison in the city. On "departed" (απεστη) see on verse Acts 12:7.