Passage 7.27.9
Πελλήνης δὲ ὅσον στάδια ἑξήκοντα ἀπέχει τὸ Μύσαιον, ἱερὸν Δήμητρος Μυσίας· ἱδρύσασθαι δὲ αὐτὸ Μύσιόν φασιν ἄνδρα Ἀργεῖον, ἐδέξατο δὲ οἴκῳ Δήμητρα καὶ ὁ Μύσιος λόγῳ τῷ Ἀργείων. ἔστι δὲ ἄλσος ἐν τῷ Μυσαίῳ, δένδρα ὁμοίως τὰ πάντα, καὶ ὕδωρ ἄφθονον ἄνεισιν ἐκ πηγῶν. ἄγουσι δὲ καὶ ἑορτὴν τῇ Δήμητρι ἐνταῦθα ἡμερῶν ἑπτά·
The sanctuary of Mysian Demeter, called Mysaeum, is about sixty stades distant from Pellene. They say it was founded by Mysius, an Argive man, who, according to Argive tradition, hosted Demeter in his house. At Mysaeum there is a grove, the trees of which are all alike, and abundant water flows there from springs. Here they also hold a festival in honor of Demeter, lasting seven days.