Genesis 15:7-10

7He also said to him, “I am the LORD, who brought you out of Ur of the Chaldeans to give you this land to take possession of it.”

8But Abram said, “Sovereign LORD, how can I know that I will gain possession of it?”

9So 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.” 10Abram 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.