Genesis 15:8-11

But Abram said, “Lord GOD, by what [proof] will I know that I will inherit it?” So God 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.” So Abram brought all these to Him and cut them down the middle, and laid each half opposite the other; but he did not cut the birds. The birds of prey swooped down on the carcasses, but Abram drove them away.