Sir Richard C. Jebb, Commentary on Sophocles: Trachiniae

πόθεν ἔστ̓, ‘whence are ye?’ Of what stock? Can ye be indeed of Hellenic race, and yet so heartlessly ungrateful? Cp. Od.17. 373“πόθεν γένος εὔχεται εἶναι”;—Hermann explains πόθεν ἐστέ as=‘whence do ye appear to aid me?’ (unde mihi auxilio adestis?):—a complaint that they do not appear. He compares Od.2. 267“σχεδόθεν δέ οἱ ἦλθεν Ἀθήνη”: but might better have cited Il.16. 800“σχεδόθεν δέ οἱ ἦεν ὄλεθρος”. The version is tenable in itself, but is not well suited to the context. Heracles is addressing the men who are actually around him,—the Greeks (some of them his own mercenaries) who have brought him from Euboea. Cp. the very similar passage in Ph.1203 ff.: “ἀλλ̓, ὦ ξένοι, ἕν γέ μοι εὖχος ὀρέξατε....ξίφος, εἴ ποθεν”, | “ἢ γένυν, ἢ βελέων τι, προπέμψατε”. He is not making a merely rhetorical appeal to the absent,—‘all those who had been benefited by him,’ as the schol. says. In that case, he would not say, “πάντων Ἑλλάνων ἀδικώτατοι ἄνδρες”: he had toiled for all Hellenes.