'Pillar of Fire' in the Bible

Moreover thou leddest them in the day by a cloudy pillar; and in the night by a pillar of fire, to give them light in the way wherein they should go.

Yet thou in thy manifold mercies forsookest them not in the wilderness: the pillar of the cloud departed not from them by day, to lead them in the way; neither the pillar of fire by night, to shew them light, and the way wherein they should go.