Exodus 12:40 states:
> Now the length of time the Israelite people lived in Egypt was 430 years.

Some question if this contradicts Genesis 15:13, which mentions 400 years. There is no contradiction. Exodus gives the total number of years that the people lived in Egypt, while Genesis gives the number of years they would be enslaved and mistreated. The enslavement and mistreatment did not start right away upon their arrival. The promises were made to Abraham and his seed. The last statement of promise recorded was to Jacob (Gen. 28:15), and that is where the 430 years dates from.

It is argued that God warns Abraham of rough times ahead without being specific (Genesis 15:13-16) because the future is open and unknown. Yet this is just as well a way for God to forestall any pre-emptive actions on Abraham's part. If Abraham had been told that his descendants would fight Canaanites, how much temptation would there be for Abraham to attack those who were contextually innocent predecessors of his descendants' enemies? If God possessed exhaustive foreknowledge, He would likely be ambiguous as well when it came to telling people what was up with their future, keeping specifics under wraps or limited to certain persons. For Abraham to know that much would be "too much information".