Genesis 15:13-16

13God said to Abram, “You can know for sure that your descendants will live in a land that is not their own, where they will be slaves, and they will be oppressed for 400 years.

14But I will punish the nation they serve, and after that they will come out with many possessions.

15But you will die in peace and be buried at a very old age.

16In the fourth generation your descendants will come back here, because the sin of the Amorites will not have run its course until then.”