Genesis 15:8-12

Abram said, “Master GOD, how am I to know this, that it will all be mine?” GOD said, “Bring me a heifer, a goat, and a ram, each three years old, and a dove and a young pigeon.” He brought all these animals to him, split them down the middle, and laid the halves opposite each other. But he didn’t split the birds. Vultures swooped down on the carcasses, but Abram scared them off. As the sun went down a deep sleep overcame Abram and then a sense of dread, dark and heavy.