Genesis 15:11-13

15:11 When birds of prey came down on the carcasses, Abram drove them away.

15:12 When the sun went down, Abram fell sound asleep, and great terror overwhelmed him. 15:13 Then the Lord said to Abram, “Know for certain that your descendants will be strangers in a foreign country. They will be enslaved and oppressed for four hundred years.