Genesis 15:8-12, 17-18

But Abram replied, “O Sovereign LORD, how can I be sure that I will actually possess it?” The LORD told 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 presented all these to him and killed them. Then he cut each animal down the middle and laid the halves side by side; he did not, however, cut the birds in half. Some vultures swooped down to eat the carcasses, but Abram chased them away. As the sun was going down, Abram fell into a deep sleep, and a terrifying darkness came down over him.

After the sun went down and darkness fell, Abram saw a smoking firepot and a flaming torch pass between the halves of the carcasses. So the LORD made a covenant with Abram that day and said, “I have given this land to your descendants, all the way from the border of Egypt to the great Euphrates River