Passage 2.29.9
παρὰ δὲ τὸ Αἰάκειον Φώκου τάφος χῶμά ἐστι περιεχόμενον κύκλῳ κρηπῖδι, ἐπίκειται δέ οἱ λίθος τραχύς· καὶ ἡνίκα Φῶκον Τελαμὼν καὶ Πηλεὺς προηγάγοντο ἐς ἀγῶνα πεντάθλου καὶ περιῆλθεν ἐς Πηλέα ἀφεῖναι τὸν λίθον---οὗτος γὰρ ἀντὶ δίσκου σφίσιν ἦν---, ἑκὼν τυγχάνει τοῦ Φώκου. ταῦτα δὲ ἐχαρίζοντο τῇ μητρί· αὐτοὶ μὲν γὰρ ἐγεγόνεσαν ἐκ τῆς Σκίρωνος θυγατρός, Φῶκος δὲ οὐκ ἐκ τῆς αὐτῆς, ἀλλʼ ἐξ ἀδελφῆς Θέτιδος ἦν, εἰ δὴ τὰ ὄντα λέγουσιν Ἕλληνες. Πυλάδης τέ μοι καὶ διὰ ταῦτα φαίνεται καὶ οὐκ Ὀρέστου φιλίᾳ μόνον βουλεῦσαι Νεοπτολέμῳ τὸν φόνον.
Next to the Aiakeion is the tomb of Phokos, which consists of an earthen mound, enclosed around by a low stone border; upon this rests a rough stone. When Telamon and Peleus challenged Phokos to compete in the pentathlon, the stone was used by them instead of a discus; and at the moment it came around to Peleus to throw, it struck Phokos, and it seems that this deed was intentional. They committed this act to please their mother; for while they themselves were born from the daughter of Skiron, Phokos was not from the same mother, but from the sister of Thetis, if indeed the stories told by the Greeks are true. And, from these events, it appears to me also that Pylades helped plot the murder of Neoptolemos not merely out of friendship for Orestes alone.