Genesis 15:9

5And he brought him forth abroad, and said, Look now toward heaven, and tell the stars, if thou be able to number them: and he said unto him, So shall thy seed be.

6And he believed in the Lord; and he counted it to him for righteousness.

7And he said unto him, I am the Lord that brought thee out of Ur of the Chaldees, to give thee this land to inherit it.

8And he said, Lord God, whereby shall I know that I shall inherit it?

9And he said unto him, Take me an heifer of three years old, and a she goat of three years old, and a ram of three years old, and a turtledove, and a young pigeon.

10And he took unto him all these, and divided them in the midst, and laid each piece one against another: but the birds divided he not.

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 unto Abram, Know of a surety 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;