Genesis 15:5, 8-10, 17-21 ESV – And he brought him outside and said, “Look toward heaven, and number the stars, if you are able to number them.” Then he said to him, “So shall your offspring be.” … But he said, “O Lord GOD, how am I to know that I shall possess it?” He said to him, “Bring me a heifer three years old, a female goat three years old, a ram three years old, a turtledove, and a young pigeon.” And he brought him all these, cut them in half, and laid each half over against the other. But he did not cut the birds in half. … When the sun had gone down and it was dark, behold, a smoking fire pot and a flaming torch passed between these pieces. On that day the LORD made a covenant with Abram, saying, “To your offspring I give this land, from the river of Egypt to the great river, the river Euphrates, the land of the Kenites, the Kenizzites, the Kadmonites, the Hittites, the Perizzites, the Rephaim, the Amorites, the Canaanites, the Girgashites and the Jebusites.”

Peter Gentry and Stephen Wellum, Kingdom Through Covenant (Wheaton: Crossway, 2012), 251.

The ceremony or ritual described here is somewhat strange. Nonetheless, as verse 18 clearly states, this ceremony formalises a covenant between God and Abram. The normal or standard terminology “to cut a covenant” is used. The interpretation of this mysterious rite is much discussed.

The ceremony of covenant making involves an oath in which the covenant partners bring the curse of death upon themselves if they are not faithful to the covenant relationship and promises. Walking between the animals cut in half is a way of saying, “May I become like these dead animals if I do not keep my promise(s) and my oath.” Scholars describe this as a self-maledictory oath, i.e., an oath where one brings the curse of death upon oneself for violating the covenant commitments. The detail with which covenant making ceremonies are narrated varies from text to text. The covenant making in Jeremiah 34:18–20 is also explicit about walking between the pieces of the animal sacrificed for the rite:

[18] The men who have violated my covenant and have not fulfilled the terms of the covenant they made before me, I will treat like the calf they cut in two and then walked between its pieces. [19] The leaders of Judah and Jerusalem, the court officials, the priests and all the people of the land who walked between the pieces of the calf, [20] I will hand over to their enemies who seek their lives. Their dead bodies will become food for the birds of the air and the beasts of the earth. (niv)

In the vision given to Abram, a “smoking firepot and a blazing torch” pass between the dead pieces. What would these represent? When we remember that Genesis was a book given to the Israelite people at the time of entering the land of Canaan, we can see from that perspective, i.e., after the exodus event, that smoke and fire are symbols of God’s presence. The angel of the Lord first appeared to Moses in the flames of a burning bush (Ex. 3:2). During the desert journey, God appears as cloud and fire (Ex. 13:21). At Mount Sinai, his presence is manifested by smoke and fire (Ex. 19:18; 20:18). The fact that only God passes between the pieces is quite remarkable and shows that the promise depends upon him and him alone.
Ray Vander Laan has nicely expressed the powerful communication of the covenant making ritual in Genesis 15:

Ray Vander Laan with Judith Markham, Echoes of His Presence: Stories of the Messiah from the People of His Day (Colorado Springs: Focus on the Family, 1996), 8–9.

What an awesome God we have! What incredible love he has for his creatures!

Imagine! The Creator of the universe, the holy and righteous God, was willing to leave heaven and come down to a nomad’s tent in the dusty, hot desert of Negev to express his love for his people.

“Bring me a heifer, a goat and a ram . . . along with a dove and a young pigeon,” God told Abraham. Then, when those animals had been sacrificed and laid out on both sides of their shed blood, God made a covenant. To do that, he walked “barefoot,” in the form of a blazing torch, through the path of blood between the animals.

Think of it. Almighty God walking barefoot through a pool of blood! The thought of a human being doing that is, to say the least, unpleasant. Yet, God, in all his power and majesty, expressed his love that personally. By participating in that traditional, Near Eastern covenant-making ceremony, he made it unavoidably clear to the people of that time, place and culture what he intended to do.

“I love you so much, Abraham,” God was saying, “and I promise that this covenant will come true for you and your children. I will never break My covenant with you. I’m willing to put My own life on the line to make you understand.”

Picturing God passing through that gory path between the carcasses of animals, imagining the blood splashing as he walked, helps us recognize the faithfulness of God’s commitment. He was willing to express, in terms his chosen people could understand, that he would never fail to do what he promised. And he ultimately fulfilled his promise by giving his own life, his own blood, on the cross.

Because we look at God’s dealings with Abraham as some remote piece of history in a far-off land, we often fail to realize that we, too, are part of the long line of people with whom God made a covenant on that rocky plain near Hebron. And like those who came before us, we have broken that covenant.

When he walked in the dust of the desert and through the blood of the animals Abraham had slaughtered, God was making a promise to all the descendants of Abraham—to everyone in the household of faith. When God splashed through the blood, he did it for us.

We’re not simply individuals in relationship to God, we’re part of a long line of people marching back through history, from our famous Jewish ancestors David, Hezekiah, and Peter to the millions of unknown believers; from the ancient Israelites and the Jewish people of Jesus’ day to the Christian community dating from the early church. We’re part of a community of people with whom God established relationship in the dust and sand of the Negev.

But there’s more. When God made covenant with his people, he did something no human being would have even considered doing. In the usual blood covenant, each party was responsible for keeping only his side of the promise. When God made covenant with Abraham, however, he promised to keep both sides of the agreement.

“If this covenant is broken, Abraham, for whatever reason—for My unfaithfulness or yours—I will pay the price,” said God. “If you or your descendants, for whom you are making this covenant, fail to keep it, I will pay the price in blood.”

And at that moment, Almighty God pronounced the death sentence on his Son Jesus.