Sir Richard C. Jebb, Commentary on Sophocles: Trachiniae

κῆρες, here merely ‘calamities,’ “συμφοραί”, a sense recognised by Hesych. s. v. “κῆρες”. The sing. oft. has this meaning (cp. 454): but the plur. usu. denotes either (a) ‘the Fates,’ as in O. T.472, or at least ‘death-dooms,’ as in Il.12. 326.

ἀλλ᾽ ἄφαρ βέβακε: the subject is each of the preceding nouns, the verb agreeing in number with the nearest ( O. C.8 n.): ‘but (each) is suddenly gone (from one), while joy, and the loss of it, come to another man in his turn.’

τῷδ̓ is opposed to the “τῷ μὲν” implied in the preceding clause. It is true that the main point is the changing experience of the individual, rather than the transference of joy or woe to his neighbour. But these two notions are closely linked here by the image of joy and woe coming round, as the Bear revolves about the pole. Cp. Her.1. 207(Croesus to Cyrus), “ἐκεῖνο πρῶτον μάθε, ὡς κύκλος τῶν ἀνθρωπηίων ἐστὶ πρηγμάτων, περιφερόμενος δὲ οὐκ ἐᾷ αἰεὶ τοὺς αὐτοὺς εὐτυχέειν”.—For χαίρειν τε καὶ στέρεσθαι as nomin. (without art.) to ἐπέρχεται, cp. Aesch. Ag.181“παρ᾽ ἄκοντας ἦλθε σωφρονεῖν”.

Other views are as follows. (1) The constr. is, “ἀλλὰ χαίρειν τε καὶ στέρεσθαι ἄφαρ βέβακε” (“τῷ μέν”), “τῷ δ᾽ ἐπέρχεται”. This is less simple. (2) “τῷ δ̓”=simply ‘and to him,’—i.e., to the person from whom woe or joy ‘has gone.’ But: (a) “τῷ δ̓” surely implies an antithesis. (b) The clause “τῷ δ᾽ ἐπέρχεται κ.τ.λ.” would thus mean merely,—‘and then his experiences begin over again.’