Genesis 15:9-11

So the LORD said to him, “Bring me a heifer, a goat and a ram, each three years old, along with a dove and a young pigeon.” Abram brought all these to him, cut them in two and arranged the halves opposite each other; the birds, however, he did not cut in half. Then birds of prey came down on the carcasses, but Abram drove them away.