Exodus 12:37-42Revised Standard Version (RSV)
37 And the people of Israel journeyed from Ram′eses to Succoth, about six hundred thousand men on foot, besides women and children. 38 A mixed multitude also went up with them, and very many cattle, both flocks and herds. 39 And they baked unleavened cakes of the dough which they had brought out of Egypt, for it was not leavened, because they were thrust out of Egypt and could not tarry, neither had they prepared for themselves any provisions.
40 The time that the people of Israel dwelt in Egypt was four hundred and thirty years. 41 And at the end of four hundred and thirty years, on that very day, all the hosts of the Lord went out from the land of Egypt. 42 It was a night of watching by the Lord, to bring them out of the land of Egypt; so this same night is a night of watching kept to the Lord by all the people of Israel throughout their generations.