Diodorus on the Greek Cultural Debt to Egypt (based on Oldfather's tr.)

But now that we have examined these matters we must enumerate what Greeks, who have won fame for their wisdom and learning, visited Egypt in ancient times in order to become acquainted with its customs and learning. For the priests of Egypt recount from the records of their sacred books that they were visited in early times by Orpheus, Musaeus, Melampus, and Daedalus, also by the poet Homer and Lycurgus of Sparta, later by Solon of Athens and the philosopher Plato, and that there came also Pythagoras of Samos and the mathematician Eudoxus, as well as Democritus of Abdera and Oenopides of Chios. As evidence for the visits of all these men they point in some cases to their statues and in others to places or buildings which bear their names, and they offer proofs from the branch of learning which each one of these men pursued, arguing that all the things for which they were admired among the Greeks were borrowed from Egypt. (1.96)

Orpheus, for instance, brought from Egypt most of his mystic ceremonies, the orgiastic rites that accompanied his wanderings, and his fabulous account of his experiences in Hades. For the rite of Osiris is the same as that of Dionysus, and that of Isis very similar to that of Demeter, the names alone having been interchanged; and the punishments in Hades of the unrighteous, the Fields of the Righteous, and the fantastic conceptions, current among the many, which are figments of the imagination all these were introduced by Orpheus in imitation of Egyptian funeral customs. (1.96)

And as proof of the presence of Homer they adduce various pieces of evidence , and especially the healing drink which brings forgetfulness of all past evils, which was given by Helen to Telemachus in the home of Menelaus [in Book Four of the Odyssey] ... for, they allege, even to this day the women of this city [Thebes in Egypt] use this powerful remedy. (1.97)

Lycurgus also and Plato and Solon, they say, incorporated many Egyptian customs into their own legislation. And Pythagoras learned from Egyptians his teachings about the gods, his geometrical propositions and theory of numbers, as well as the transmigration of souls into every living thing. (1.98)