'Pillar of Fire' in the Bible

And the Lord went before them by day in a pillar of cloud, guiding them on their way; and by night in a pillar of fire to give them light: so that they were able to go on day and night:

The pillar of cloud went ever before them by day, and the pillar of fire by night.

And in the morning watch, the Lord, looking out on the armies of the Egyptians from the pillar of fire and cloud, sent trouble on the army of the Egyptians;