Plato, Laws 681e

ὃ μετὰ τὸ δεύτερον καὶ Ὅμηρος ἐπεσημήνατο, λέγων τὸ τρίτον οὕτω γεγονέναι. κτίσσε δὲ Δαρδανίην γάρ πού φησιν, ἐπεὶ οὔπω Ἴλιος ἱρὴ ἐν πεδίῳ πεπόλιστο, πόλις μερόπων ἀνθρώπων, ἀλλʼ ἔθʼ ὑπωρείας ᾤκουν πολυπιδάκου Ἴδης.

What form is that? The same that Homer himself mentioned next to the second, when he said that the third form arose in this way. His verses run thus— Dardania he founded when as yet The Holy keep of Ilium was not built Upon the plain, a town for mortal folk, But still they dwelt upon the highland slopes Of many-fountained Ida.