Passage 9.37.6
ἵστησιν οὖν ὑπὲρ τῶν ἀγγείων, ἐν οἷς ὅ τε ἄργυρος ἐνῆν καὶ ὁ χρυσός οἱ, πάγας ἤ τι καὶ ἄλλο ὃ τὸν ἐσελθόντα καὶ ἁπτόμενον τῶν χρημάτων καθέξειν ἔμελλεν. ἐσελθόντος δὲ τοῦ Ἀγαμήδους τὸν μὲν ὁ δεσμὸς κατεῖχε, Τροφώνιος δὲ ἀπέτεμεν αὐτοῦ τὴν κεφαλήν, ὅπως μὴ ἡμέρας ἐπισχούσης ἐκεῖνος γένοιτο ἐν αἰκίαις καὶ αὐτὸς μηνυθείη μετέχων τοῦ τολμήματος.
Therefore, he set up snares or some other device above the vessels in which he kept his silver and gold, designed to catch and hold anyone who entered and touched the treasure. Thus, when Agamedes went inside, the trap held him fast; but Trophonios cut off his head, ensuring that, when daylight came, his brother would not be found alive and tortured, and that he himself would not be implicated as an accomplice in the crime.