ἄας
From LSJ
οὐ γὰρ ἂν τό γε πραχθὲν ἀγένητον θείη → since he cannot make what was done as though it had not come to pass
English (LSJ)
A to-morrow or the day after to-morrow, gen. of ἄα, = ἠώς, read by Zenod. for ἠοῦς in Il.8.470 (cf. Sch.Ven.); as Adv. in Boeot., Hsch.; cf. ἀές.
Greek (Liddell-Scott)
ἄᾱς: αὔριον ἢ μεθαύριον, γεν. τοῦ ἄα, = ἠώς, ὡς ὁ Ζηνόδ. ἀνεγίνωσκεν ἀντὶ ἠοῦς, ἐν Ἰλ. Θ. 470 (ὅρ. Σχολ. Ἑνετ.). Ἐν χρήσει παρὰ Βοιωτ. ὡς ἐπίρρ. Ἡσύχ.