Passage 3.1.6
συναρέσαι γὰρ τῇ Πυθίᾳ φασίν. Ἀριστοδήμῳ δὲ αὐτῷ πρότερον τὴν τελευτὴν συμβῆναι λέγουσιν ἐν Δελφοῖς πρὶν ἢ Δωριέας κατελθεῖν ἐς Πελοπόννησον. οἱ μὲν δὴ ἀποσεμνύνοντες τὰ ἐς αὐτὸν τοξευθῆναι λέγουσιν Ἀριστόδημον ὑπὸ Ἀπόλλωνος, ὅτι οὐκ ἀφίκοιτο ἐπὶ τὸ μαντεῖον, παρὰ δὲ Ἡρακλέους ἐντυχόντος οἱ πρότερον πύθοιτο ὡς ἐς Πελοπόννησον Δωριεῦσι γενήσεται ἥδε ἡ κάθοδος· ὁ δὲ ἀληθέστερος ἔχει λόγος Πυλάδου τοὺς παῖδας καὶ Ἠλέκτρας, ἀνεψιοὺς ὄντας Τισαμενῷ τῷ Ὀρέστου, φονεῦσαι τὸν Ἀριστόδημον.
For they say he pleased the Pythia. But Aristodemus himself, it is told, met his death at Delphi before the Dorians descended into the Peloponnesus. Some indeed glorify his story, saying that Aristodemus was shot by Apollo, because he had not approached the oracle but had previously inquired from Heracles, who appeared to him, how the planned descent of the Dorians into the Peloponnesus would turn out. The more truthful account, however, maintains that the sons of Pylades and Electra, cousins of Tisamenus son of Orestes, killed Aristodemus.