Passage 10.32.6
ἔστι δὲ καὶ τοῖς ἐπὶ ποταμῷ Ληθαίῳ Μάγνησιν Αὐλαὶ καλούμενον χωρίον· ἐνταῦθα Ἀπόλλωνι ἀνεῖται σπήλαιον, μεγέθους μὲν εἵνεκα οὐ πολλοῦ θαύματος, τὸ δὲ ἄγαλμα τοῦ Ἀπόλλωνος τὰ μάλιστα ἀρχαῖον καὶ ἰσχὺν ἐπὶ ἔργῳ παρέχεται παντί· καὶ αὐτῷ ἄνδρες ἱεροὶ κατὰ κρημνῶν τε ἀποτόμων καὶ πετρῶν πηδῶσιν ὑψηλῶν καὶ ὑπερμήκη δένδρα ἐριπόντες ἐκ ῥιζῶν κατὰ τὰ στενώτατα τῶν ἀτραπῶν ὁμοῦ τοῖς ἄχθεσιν ὁδεύουσι.
There is also among the Magnesians who dwell by the river Lethaeus a place called Aulai. Here there is dedicated to Apollo a cave, which, in terms of its size, is not greatly remarkable; however, the statue of Apollo is very ancient indeed and confers strength for every undertaking. Consecrated men dedicated to the god leap from sheer precipices and high rocks, and, grasping tall trees and tearing them up by their roots, carry them along with their burdens, making their way even through the narrowest of paths.