Passage 5.4.1
λέγεται δὲ καὶ ἄλλο ἐπὶ τῷ Ὀξύλῳ τοιόνδε, ὡς τοὺς παῖδας ὑποπτεύσειε τοῦ Ἀριστομάχου, μὴ τὴν Ἠλείαν τε ἰδόντες ἀγαθὴν οὖσαν καὶ ἐξειργασμένην διὰ πάσης οὐκ ἐθελήσωσιν ἔτι αὐτῷ διδόναι τὴν γῆν, καὶ τοῦδε ἕνεκα διὰ τῶν Ἀρκάδων καὶ οὐ διὰ τῆς Ἠλείας τοῖς Δωριεῦσιν ἡγήσατο. Ὀξύλῳ δὲ σπεύσαντι ἀμαχεὶ λαβεῖν τὴν Ἠλείων ἀρχὴν Δῖος οὐκ εἶκε, πρόκλησιν δὲ ἐποιεῖτο μὴ σφᾶς παρασκευῇ τῇ πάσῃ διακινδυνεῦσαι, προκριθῆναι δὲ ἀφʼ ἑκατέρων στρατιώτην ἕνα ἐς τὴν μάχην·
Another story is also told regarding Oxylus, namely that he distrusted the sons of Aristomachus, suspecting that if they saw Elis, fertile and entirely cultivated, they would no longer wish to grant him the land. For this reason Oxylus guided the Dorians through Arcadia rather than through Elis. When Oxylus sought to seize the rule over the Eleans without a fight, Dius would not yield; instead, he proposed a challenge—rather than risking their entire armies, each side should select a single warrior for the battle.