Sir Richard C. Jebb, Commentary on Sophocles: Antigone

αὐλείων πυλῶν, the outer door (or gate) of the court-yard, the “αὔλειοι” (or “αὐλῆς”) “θύραι” of the Homeric house (Od. 18.239), in distinction from the “θύραι μεγάρου”, or inner door from the court into the men's hall. This was the “αὔλειος θύρα”, or front door, of the later Greek house, in distinction from the “μέταυλος θύρα” leading from the court to the inner part. The tragedians commonly use the more stately word “πύλαι”, rather than “θύραι”, for these outer doors of the palace: cp. Eur. Helen 431 “πύλας τε σεμνὰς ἀνδρὸς ὀλβίου τινὸς ι προσῆλθον”: ib. 438 “πρὸς αὐλείοισιν ἑστηκὼς πύλαις.”

ἐξέπεμπον, ‘sought to bring thee forth’: the act., since she had herself fetched or called Ismene; the midd. meaning to summon by a messenger, O. T. 951 “τί μ᾽ ἐξεπέμψω δεῦρο τῶνδε δωμάτων”; cp. on 161, 165. The imperf., because she speaks of the motive present to her mind while the act was being done: cp. O. C. 770 “τότ᾽ ἐξεώθεις κἀξέβαλλες”, n.