Genesis 15:9-13

9So 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.”

10Then 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.

11And when the vultures came down on the carcasses, Abram drove them away.

12Now when the sun was going down, a deep sleep fell upon Abram; and behold, horror and great darkness fell upon him.

13Then 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.