Genesis 15:8-17

And he said, “Lord GOD, how shall I know that I will inherit it?” So He said to him, “Bring Me a three-year-old heifer, a three-year-old female goat, a three-year-old ram, a turtledove, and a young pigeon.” Then he brought all these to Him and cut them in two, down the middle, and placed each piece opposite the other; but he did not cut the birds in two. And when the vultures came down on the carcasses, Abram drove them away. 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.