Herodotus, "Histories" (Book II)
47. The pig is accounted by the Egyptians an abominable animal; and first, if any of them in passing by touch a pig, he goes into the river and dips himself forthwith in the water together with his garments; and then too swineherds, though they be native Egyptians, unlike all others do not enter any of the temples in Egypt, nor is anyone willing to give his daughter in marriage to one of them or to take a wife from among them; but the swineherds both give in marriage to one another and take from one another. Now to the other gods the Egyptians do not think it right to sacrifice swine; but to the Moon and to Dionysos alone at the same time and on the same full-moon they sacrifice swine, and then eat their flesh: and as to the reason why, when they abominate swine at all their other feasts, they sacrifice them at this, there is a story told by the Egyptians; and this story I know, but it is not a seemly one for me to tell. Now the sacrifice of the swine to the Moon is performed as follows:--when the priest has slain the victim, he puts together the end of the tail and the spleen and the caul, and covers them up with the whole of the fat of the animal which is about the paunch, and then he offers them with fire; and the rest of the flesh they eat on that day of full moon upon which they have held the sacrifice, but on any day after this they will not taste of it: the poor however among them by reason of the scantiness of their means shape pigs of dough and having baked them they offer these as a sacrifice. 48. Then for Dionysos on the eve of the festival each one kills a pig by cutting its throat before his own doors, and after that he gives the pig to the swineherd who sold it to him, to carry away again; and the rest of the feast of Dionysos is celebrated by the Egyptians in the same way as by the Hellenes in almost all things except choral dances, but instead of the /phallos/ they have invented another contrivance, namely figures of about a cubit in height worked by strings, which women carry about the villages, with the privy member made to move and not much less in size than the rest of the body: and a flute goes before and they follow singing the praises of Dionysos. As to the reason why the figure has this member larger than is natural and moves it, though it moves no other part of the body, about this there is a sacred story told. 49. Now I think that Melampus the son of Amytheon was not without knowledge of these rites of sacrifice, but was acquainted with them: for Melampus is he who first set forth to the Hellenes the name of Dionysos and the manner of sacrifice and the procession of the /phallos/. Strictly speaking indeed, he when he made it known did not take in the whole, but those wise men who came after him made it known more at large. Melampus then is he who taught of the /phallos/ which is carried in procession for Dionysos, and from him the Hellenes learnt to do that which they do. I say then that Melampus being a man of ability contrived for himself an art of divination, and having learnt from Egypt he taught the Hellenes many things, and among them those that concern Dionysos, making changes in some few points of them: for I shall not say that that which is done in worship of the god in Egypt came accidentally to be the same with that which is done among the Hellenes, for then these rites would have been in character with the Hellenic worship and not lately brought in; nor certainly shall I say that the Egyptians took from the Hellenes either this or any other customary observance: but I think it most probable that Melampus learnt the matters concerning Dionysos from Cadmos the Tyrian and from those who came with him from Phenicia to the land which we now call Bœotia.