How did ancient Babylonians transfer real estate using a blood covenant?

Les explains that this was the then-typical means of transferring real estate according to the ancient Babylonian rules, which Hammurabi had more or less laid out. In pagan culture, everything was based on blood sacrifice; they did nothing without offering one. So for real estate, they killed the animals, parted the carcasses, left a walkway between the halves, and the two men transferring the property made a blood covenant, probably by a cut in the hand, shaking hands to make a contract. God then comes down and does the very same thing with Abram, while ensuring Abram has nothing to do with the covenant responsibility.