Plato, Laws 871c

ὁ θεὸς περὶ ταῦτα νόμιμα παραδῷ, πάντα ἀποτελῶν, καὶ τὴν πρόρρησιν προαγορεύων, ἴτω ἀναγκάζων τὸν δράσαντα ὑπέχειν τὴν τῆς δίκης πρᾶξιν κατὰ νόμον. ταῦτα δὲ ὅτι μὲν γίγνεσθαι χρεών ἐστι διά τινων ἐπευχῶν καὶ θυσιῶν θεοῖς τισιν οἷς τῶν τοιούτων μέλει, φόνους μὴ γίγνεσθαι κατὰ πόλεις, ῥᾴδιον ἀποφαίνεσθαι νομοθέτῃ· τίνες δʼ εἰσὶν οἱ θεοὶ καὶ τίς ὁ τρόπος τῶν τοιούτων δικῶν τῆς εἰσαγωγῆς ὀρθότατα πρὸς τὸ θεῖον ἂν γιγνόμενος εἴη, νομοφύλακες μετʼ

and he shall recite the pronouncement of warning; and thus he shall go and compel the culprit to submit to the execution of the penalty according to law. That it is necessary that these proceedings should be accompanied by certain invocations and sacrifices to those gods whose concern it is that murders should not occur in States, it is easy for the lawgiver to demonstrate: who these gods are, and what method for bringing such prosecutions would be the most correct in point of ritual,—this the Law-wardens, in conjunction with the interpreters and seers and with the god, shall ordain;