Sir Richard C. Jebb, Commentary on Sophocles: Oedipus Tyrannus

[1084] “Having sprung of such parentage （ἐκφὺς, whereas φύς would be merely ”having been born such “） I will never afterwards prove （ἐξέλθοιμι, evadam, cp. 1011） another man ” （ἄλλος, i.e. false to my own nature）. The text is sound. The license of ποτ᾽ at the beginning of 1085 is to be explained on essentially the same principle as μέλας δ᾽ ι, etc. （29, cp. 785, 791） at the end of a verse; viz. that, where the movement of the thought is rapid, one verse can be treated as virtually continuous with the next: hence, too, Soph. Aj. 986 “οὐχ ὅσον τάχος ι δῆτ᾽ αὐτὸν ἄξεις δεῦρο”: Soph. Phil. 66 “εἰ δ᾽ ἐργάσει ι μὴ ταῦτα.” So here Soph. has allowed himself to retain ἔτι ι ποτέ in their natural connexion instead of writing ἔτι ι ἄλλος ποτ᾽. The genuineness of ποτ᾽ is confirmed by the numerous instances in which Soph. has combined it with ἔτι, as above, 892, below, 1412: Soph. Aj. 98, 687: Soph. Trach. 830, 922.