Plutarch, De Iside et Osiride 35 (part 2)

καὶ θύουσιν οἱ Ὅσιοι θυσίαν ἀπόρρητον ἐν τῷ ἱερῷ τοῦ Ἀπόλλωνος, ὅταν αἱ Θυιάδες ἐγείρωσι τὸν Λικνίτην, ὅτι δʼ οὐ μόνον τοῦ οἴνου Διόνυσον, ἀλλὰ καὶ πάσης ὑγρᾶς φύσεως Ἕλληνες ἡγοῦνται κύριον καὶ ἀρχηγόν, ἀρκεῖ Πίνδαρος μάρτυς εἶναι λέγων δενδρέων δὲ νομὸν Διόνυσος πολυγαθὴς αὐξάνοι, ἁγνὸν φέγγος ὀπώρας. διὸ καὶ τοῖς τὸν Ὄσιριν σεβομένοις ἀπαγορεύεται δένδρον ἥμερον ἀπολλύναι καὶ πηγὴν ὕδατος ἐμφράττειν.

That Osiris is identical with Dionysus who could more fittingly know than yourself, Clea ? For you are ii t the head of the inspired maidens of Delphi, and have been consecrated by your father and mother in the holy rites of Osiris. If, however, for the benefit of others it is needful to adduce proofs of this identity, let us leave undisturbed what may not be told, but the public ceremonies which the priests perform in the burial of the Apis, when they convey his body on an improvised bier, do not in any way come short of a Bacchic procession; for they fasten skins of fawns about themselves, and carry Bacchic wands and indulge in shoutings and movements exactly as do those who are under the spell of the Dionysiac ecstasies. For the same reason many of the Greeks make statues of Dionysus in the form of a bull; and the women of Elis invoke him, praying that the god may come with the hoof of a bull; and the epithet applied to Dionysus among the Argives is Son of the Bull. They call him up out of the water by the sound of trumpets, at the same time casting into the depths a lamb as an offering to the Keeper of the Gate. The trumpets they conceal in Bacchic wands, as Socrates has stated in his treatise on The Holy Ones. Furthermore, the tales regarding the Titans and the rites celebrated by night agree with the accounts of the dismemberment of Osiris and his revivification and regenesis. Similar agreement is found too in the tales about their sepulchres. The Egyptians, as has already been stated, point out tombs of Osiris in many places, and the people of Delphi believe that …