Genesis 15:17

And it came to pass that, when the sun went down and it was dark, behold a smoking furnace and a burning lamp that passed between those pieces. These happenings completed the symbolical events connected with the founding of the covenant between the Lord and Abram. A smoking furnace, like that used in potteries, and a torch, or cresset, passed between the halves of the animals, symbols of the glory of the Lord in fire. The animals thus are a type of the descendants of Abraham, of the children of Israel, as they were tortured almost unto death, especially by the Egyptians. The birds of prey are pictures of these enemies of Israel. That these vultures were driven away indicates that the Lord would deliver His people for the sake of the promise made to Abram. The great darkness and the horror pointed to the severity of the miseries and tribulations which would strike the Israelites. But that finally the glory of the Lord passed between the halves of the animals showed that God would at the last bring help to His people and deliver them from the hands of all their enemies.