Passage 9.16.5
τὸ δὲ τῆς Δήμητρος ἱερὸν τῆς Θεσμοφόρου Κάδμου καὶ τῶν ἀπογόνων οἰκίαν ποτὲ εἶναι λέγουσι· Δήμητρος δὲ ἄγαλμα ὅσον ἐς στέρνα ἐστὶν ἐν τῷ φανερῷ. καὶ ἀσπίδες ἐνταῦθα ἀνάκεινται χαλκαῖ· Λακεδαιμονίων δέ, ὁπόσοι τῶν ἐν τέλει περὶ Λεῦκτρα ἐτελεύτησαν, φασὶν εἶναι.
They say that the sanctuary of Demeter Thesmophoros was once the house of Cadmus and his descendants. The image of Demeter standing there is visible only down to the chest. In this place bronze shields are also dedicated, said to belong to those Spartan commanders who fell in the battle at Leuctra.