Genesis 43:32

They set on for him by himself; partly because the dignity of his place, and the custom of princes, required this state; and partly for the reason here following. That is an abomination unto the Egyptians; not so much from their pride and disdain of other people, as from their superstition and idolatry; partly because they worshipped the creatures which the Hebrews and others did commonly eat; and partly because of some peculiar rites and customs which they had in the dressing and ordering of their diet. Whence Herodotus affirms, that the Egyptians would not use the pots nor knives of the Grecians about their food. Compare Genesis 46:34. See there, Exodus 8:26.