Passage 2.5.1
ἀνελθοῦσι δὲ ἐς τὸν Ἀκροκόρινθον ναός ἐστιν Ἀφροδίτης· ἀγάλματα δὲ αὐτή τε ὡπλισμένη καὶ Ἥλιος καὶ Ἔρως ἔχων τόξον. τὴν δὲ πηγήν, ἥ ἐστιν ὄπισθεν τοῦ ναοῦ, δῶρον μὲν Ἀσωποῦ λέγουσιν εἶναι, δοθῆναι δὲ Σισύφῳ· τοῦτον γὰρ εἰδότα, ὡς εἴη Ζεὺς ἡρπακὼς Αἴγιναν θυγατέρα Ἀσωποῦ, μὴ πρότερον φάναι ζητοῦντι μηνύσειν πρὶν ἤ οἱ καὶ ἐν Ἀκροκορίνθῳ γένοιτο ὕδωρ· δόντος δὲ Ἀσωποῦ μηνύει τε οὕτως καὶ ἀντὶ τοῦ μηνύματος δίκην---ὅτῳ πιστὰ---ἐν Ἅιδου δίδωσιν. ἤκουσα δὲ ἤδη τὴν Πειρήνην φαμένων εἶναι ταύτην καὶ τὸ ὕδωρ αὐτόθεν ὑπορρεῖν τὸ ἐν τῇ πόλει.
Upon ascending to Acrocorinth there is a temple of Aphrodite. The statues there include Aphrodite herself in armor, as well as Helios and Eros holding a bow. Regarding the spring located behind the temple, it is said to be a gift of Asopus, given to Sisyphus. For Sisyphus, knowing that Zeus had ravished Aegina, Asopus' daughter, refused to reveal this to Asopus, who was seeking his daughter, until water was first provided to him on Acrocorinth. When Asopus granted this favor, Sisyphus told him the truth, and for this informing, according to what is believed, he now pays the penalty in Hades. I have also heard that this spring is called Peirene, and its waters flow underground toward the city.