Passage 6.22.6
λέγουσι δὲ οἱ Ἠλεῖοι καὶ ἔπος ἐς τὴν Πύλον ταύτην ἔχειν τῶν Ὁμήρου, γένος δʼ ἦν ἐκ ποταμοῖο Ἀλφειοῦ, ὅστʼ εὐρὺ ῥέει Πυλίων διὰ γαίης, Hom. Il. 5.544 καὶ ἐμὲ ἔπειθον λέγοντες· ῥεῖ γὰρ δὴ διὰ τῆς χώρας ταύτης ὁ Ἀλφειός, ἐς δὲ ἄλλην Πύλον οὐκ ἔστιν ἐπενεγκεῖν τὸ ἔπος· Πυλίων γὰρ τῶν ὑπὲρ νήσου τῆς Σφακτηρίας οὐ πέφυκεν ἀρχὴν διοδεύειν τὴν γῆν ὁ Ἀλφειός, οὐ μὴν οὐδὲ ἐν τῇ Ἀρκάδων Πύλον ποτὲ ὀνομασθεῖσαν ἴσμεν πόλιν.
The Eleans say that there is also a verse from Homer referring to this Pylos, "whose race was from the river Alpheius, which flows broad through the land of the Pylians," and indeed they persuaded me as well, stating that the Alpheius does flow through this territory, and the verse cannot be applied to another Pylos. For the Alpheius does not naturally flow through the land of the Pylians beyond the island of Sphacteria, nor was there ever, so far as we know, a city called Pylos in Arcadia.