Passage 3.25.8
ἔστι δὲ ἐπὶ Ταινάρῳ καὶ πηγή, νῦν μὲν οὐδὲν ὥστε καὶ θαῦμα εἶναι παρεχομένη, πρότερον δὲ τοῖς ἐνιδοῦσιν ἐς τὸ ὕδωρ τοὺς λιμένας---φασὶ--- καὶ τὰς ναῦς θεάσασθαι παρεῖχε. τοῦτο ἔπαυσε γυνὴ τὸ ὕδωρ μὴ καὶ τοῦ λοιποῦ τοιαῦτα ἐπιδείκνυσθαι, μεμιασμένην ἐναποπλύνασα ἐσθῆτα.
At Taenarum there is also a spring which nowadays displays nothing remarkable; but formerly, as they say, those who looked into its water used to behold harbors and ships. A woman caused this marvel to cease and prevented such visions from appearing ever again by washing into it clothing that had been defiled.