All the Hebrew people packed up their belongings & left Egypt for the new land that God had promised them.
The Lord went before them by day in a pillar of cloud, to lead them the way, and by night in a pillar of fire, to give them light.
When Pharaoh & his army came close to the Hebrew people, Moses said, "The Lord shall fight for you, and you shall hold your peace."
The pillar of the cloud came between the camp of Israel & the camp of Egyptians.
It was the cloud of darkness for Egyptians & a cloud of light for Israel