Acts 12:13

αὐτοῦ for τοῦ Πέτρου with אABDLP. Vulg. ‘eo.’

13. τὴν θύραν τοῦ πυλῶνος, the door of the gate. θύρα is the wicket which was opened for any one’s admission, while πυλών is the porch into which admission was obtained through the θύρα. ἡ θύρα τοῦ πυλῶνος occurs in the LXX. Ezekiel 40:11; also in Judges 18:16-17, in which latter place the expression applies to the gate of a city, which had also its wicket.

ὑπακοῦσαι, to hearken. Perhaps we have here a trace of the danger which at this time surrounded the disciples from this zeal for Judaism on the part of Herod. Saul had entered into every house and carried off men and women to prison (Acts 8:3), and there was a prospect of a like persecution. So Rhoda was not minded to open till she knew who was seeking for admission.