Exodus 12:37-39

37And the children of Israel journeyed from Rameses to Succoth, about six hundred thousand on foot that were men, besides children. 38And a mixed multitude went up also with them; and flocks, and herds, even very many cattle.1 39And they baked unleavened cakes of the dough which they brought from Egypt, for it was not leavened; because they were driven from Egypt, and could not tarry, neither had they prepared for themselves any food.