Tharsei

Ἐπιρρητέον δὲ καὶ τῷ τοῦ Αἰσχύλου
θάρσει· πόνου γὰρ ἄκρον οὐκ ἔχει χρόνον [fr. 352]
ὅτι τοῦτ’ ἐστὶ τὸ παρ’ Ἐπικούρου θρυλούμενον ἀεὶ καὶ θαυμαζόμενον, ὡς “οἱ μεγάλοι πόνοι συντόμως ἐξάγουσιν, οἱ δὲ χρόνιοι μέγεθος οὐκ ἔχουσιν.” ὧν τὸ μὲν εἴρηκεν ὁ Αἰσχύλος ἐναργῶς, τὸ δὲ τῷ εἰρημένῳ παρακείμενόν ἐστιν· εἰ γὰρ ὁ μέγας καὶ σύντονος οὐ παραμένει πόνος, οὐκ ἔστι μέγας ὁ παραμένων οὐδὲ δυσκαρτέρητος.
(Plutarch, Pōs dei ton neon poiēmatōn akouein 36B)

And on the words of Aeschylus,
Fear not; great stress of pain is not for long,
we ought to remark that this is the oft repeated and much admired statement originating with Epicurus, namely “that great pains have no magnitude.” Of these two ideas Aeschylus has perspicuously stated the one and the other is a corollary thereto; for if great and intense pain is not lasting, then that which does not last is not great or hard to endure. (tr. Frank Cole Babbitt)