Genesis 15:8-17

8And he said, Lord GOD, by what shall I know that I shall inherit it? 9And he said to him, Take me an heifer of three years old, and a female goat of three years old, and a ram of three years old, and a turtledove, and a young pigeon. 10And he took to him all these, and divided them in the midst, and laid each piece one against another: but the birds he did not divide. 11And when the fowls came down upon the carcases, Abram drove them away.

12And when the sun was going down, a deep sleep fell upon Abram; and, lo, an horror of great darkness fell upon him. 13And he said to Abram, Know certainly that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years; 14And also that nation, which they shall serve, will I judge: and afterward shall they come out with great substance. 15And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age. 16But in the fourth generation they shall come here again: for the iniquity of the Amorites is not yet full.

17And it came to pass, that, when the sun had gone down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces.1