Theophilus to Autolycus

Since therefore they were strangers in the land of Egypt, being by birth Hebrews from the land of Chaldæa,— for at that time, there being a famine, they were obliged to migrate to Egypt for the sake of buying food there, where also for a time they sojourned; and these things befell them in accordance with a prediction of God—having sojourned, then, in Egypt for 430 years, when Moses was about to lead them out into the desert, God taught them by the law, saying, “You shall not afflict a stranger; for you know the heart of a stranger: for yourselves were strangers in the land of Egypt.”