And the settlement of the Israelites which they had settled in Egypt was four hundred and thirty years. We do not find that Israel dwelled in Israel for four hundred years. Therefore Rashi and others begin this count from the announcement to Abraham at the Covenant of the Pieces that his progeny would be exiled in a land not their own. From Rashi’s comment we can infer, explains Ketav Sofer, that mere knowledge of a future event can change a person’s mindset. Knowing their descendants would suffer in Egypt, affected the patriarchs and matriarchs so much that they themselves felt as if they too were already in Egypt.