Passage 8.41.2
ποταμὸς δὲ ὁ καλούμενος Λύμαξ ἐκδίδωσι μὲν ἐς τὴν Νέδαν παρʼ αὐτὴν ῥέων Φιγαλίαν, γενέσθαι δὲ τοὔνομά φασι τῷ ποταμῷ καθαρσίων τῶν Ῥέας ἕνεκα. ὡς γὰρ δὴ τεκοῦσαν τὸν Δία ἐκάθηραν ἐπὶ ταῖς ὠδῖσιν αἱ Νύμφαι, τὰ καθάρματα ἐς τοῦτον ἐμβάλλουσι τὸν ποταμόν· ὠνόμαζον δὲ ἄρα οἱ ἀρχαῖοι αὐτὰ λύματα. μαρτυρεῖ δὲ καὶ Ὅμηρος, ἀπολυμαίνεσθαί τε ἐπὶ λύσει τοῦ λοιμοῦ τοὺς Ἕλληνας καὶ ἐμβάλλειν τὰ λύματα εἰπὼν σφᾶς ἐς θάλασσαν.
The river called Lymax flows into the Neda, passing right by Phigalia. They say that the river acquired its name from the purifications associated with Rhea. For when Rhea had given birth to Zeus, the nymphs cleansed her after her labor and cast the impurities into this river; the ancients used to call such impurities "lymata." Homer, too, bears witness to this usage when he speaks of the Greeks purifying themselves to end the plague and throwing their impurities, which he calls "lymata," into the sea.