Sir Richard C. Jebb, Commentary on Sophocles: Oedipus at Colonus

τὸν κακούμενον ξένον. The two standard instances were subsequent, in mythical date, to the time of Oedipus. (1) Theseus, at the prayer of Adrastus king of Argos, compels Creon and his Thebans to permit the burial of the Argive warriors who had fallen in the war of Eteocles and Polynices. This is the subject of the Supplices of Eur., which continues the story of the Antigone and the Phoenissae. (2) Demophon, the son of Theseus, protects the children of Hercules against the Argive Eurystheus. This is the subject of the Heracleidae of Eur.

These two examples are cited in Her. 9.27; in the spurious “ἐπιτάφιος” ascribed to Lysias (or. 2 §§ 4-16); and in that ascribed to Demosthenes (or. 60 §§ 7, 8). Isocrates quotes them in the Panegyricus, as showing how the Athenians “διετέλεσαν τὴν πόλιν κοινὴν παρέχοντες καὶ τοῖς ἀδικουμένοις ἀεὶ τῶν Ἑλλήνων ἐπαμύνουσαν” （§ 52); also in his Encomium Helenae § 31; and again in his Panathenaicus, where he remarks that Tragedy has made them familiar to all ( § 168 “τίς οὐκ ἀκήκοε τῶν τραγῳδοδιδασκάλων Διονυσίοις”;). They figure, too, in the Platonic Menexenus, with the comment that Athens might justly be accused of too great compassion, and too much zeal for "the weaker cause": “ὡς ἀεὶ λίαν φιλοικτίρμων ἐστὶ καὶ τοῦ ἥττονος θεραπίς,” 244 E. Cp. Her. 8.142 “αἰεὶ καὶ τὸ πάλαι φαίνεσθε πολλοὺς ἐλευθερώσαντες ἀνθρώπων”. Andocides or. 3 § 28 “τοὺς κρείττους φίλους ἀφιέντες ἀεὶ τοὺς ἥττους αἱρούμεθα”.