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

[153] The bold use of ἐκτέταμαι is interpreted by φοβερὰν φρένα, δείματι πάλλων, which is to be taken in close connection with it. ἐκτείνεσθαι is not found elsewhere of mental tension ）though Dion. Hal. Comp. Verb. 15 ad fin. has ἡ τῆς διανοίας ἔκτασις καὶ τὸ τοῦ δείματος ἀπροσδόκητον. Cp. Xen. Cyrop. 1.3.11 “ἕως παρατείναιμι τοῦτον, ὥσπερ οὗτος ἐμὲ παρατείνει ἀπὸ σοῦ κωλύων,” —‘rack,’ ‘torture’ him. But παρατείνεσθαι, when used figuratively, usually meant “to be worn out,” “fatigued to death”: e.g. Plat. Lysis 204c “παραταθήσεται ὑπὸ σοῦ ἀκούων θαμὰ λέγοντος,” enecabitur, he will be tired to death of hearing it. So Xen. Mem. 3.13.6 “παρατέταμαι μακρὰν ὁδὸν πορευθείς.” Triclinius explains here, “I am prostrated by dread”（ἐκπέπληγμαι, παρ᾽ ὅσον οἱ ἐκπλαγέντες ἔκτασιν σώματος καὶ ἀκινησίαν πάσχουσιν: cp. Eur. Med. 585 “ἓν γὰρ ἐκτενεῖ σ᾽ ἔπος）”: so Soph. Phil. 858 “ἐκτέταται νύχιος” （of a sleeper）. But the context favours the other view.

πάλλων transitive, governing φρένα, making my heart to shake; not intransitive, for παλλόμενος, with φρένα as accus. of the part affected. An intransitive use of πάλλω in this figurative sense is not warranted by such instances as Aristoph. Lys. 1304 “κοῦφα πάλλων,” “lightly leaping in the dance”: Eur. El. 435 “ἔπαλλε δελφίς （”= ἐσκίρτα）, “the dolphin leaped”: Eur. El. 477 “ἵπποι ἔπαλλον” “quivered” （in death）. Cp. Aesch. PB 881 “κραδία φόβῳ φρένα λακτίζει”: so, when the speaker is identified with the troubled spirit within him, we can say φρένα πάλλω, —where φρένα has a less distinctly physical sense than in Aesch. PB 881, yet has physical associations which help to make the phrase less harsh.