Genesis 15:7-10

7And he said to him, I am Jehovah who brought thee out of Ur of the Chaldeans, to give thee this land to possess it.

8And he said, Lord Jehovah, how shall I know that I shall possess it?

9And he said to him, Take me a heifer of three years old, and a she-goat of three years old, and a ram of three years old, and a turtle-dove, and a young pigeon.

10And he took all these, and divided them in the midst, and laid the half of each opposite its fellow; but the birds he did not divide.