Genesis 15:12-18

Now when the sun was going down, a deep sleep fell upon Abram; and behold, horror and great darkness fell upon him. Then He said to Abram: “Know certainly that your descendants will be strangers in a land that is not theirs, and will serve them, and they will afflict them four hundred years. And also the nation whom they serve I will judge; afterward they shall come out with great possessions. Now as for you, you shall go to your fathers in peace; you shall be buried at a good old age. But in the fourth generation they shall return here, for the iniquity of the Amorites is not yet complete.” And it came to pass, when the sun went down and it was dark, that behold, there appeared a smoking oven and a burning torch that passed between those pieces. On the same day the LORD made a covenant with Abram, saying: “To your descendants I have given this land, from the river of Egypt to the great river, the River Euphrates