Jamieson, Fausset and Brown on Numbers 11:4

4. the mixed multitude that was among them fell a lusting--These consisted of Egyptians. [See on Ex 12:38.] To dream of banquets and plenty of animal food in the desert becomes a disease of the imagination; and to this excitement of the appetite no people are more liable than the natives of Egypt. But the Israelites participated in the same feelings and expressed dissatisfaction with the manna on which they had hitherto been supported, in comparison with the vegetable luxuries with which they had been regaled in Egypt.