Genesis 15:13-16

13God said to Abram, “Know for sure that your descendants will be strangers [living temporarily] in a land (Egypt) that is not theirs, where they will be enslaved and oppressed for four hundred years.

14But on that nation whom your descendants will serve I will bring judgment, and afterward they will come out [of that land] with great possessions.

15As for you, you shall [die and] go to your fathers in peace; you shall be buried at a good old age.

16Then in the fourth generation your descendants shall return here [to Canaan, the land of promise], for the wickedness and guilt of the Amorites is not yet complete (finished).”