'Pillar of Fire' in the Bible

Moreover in a pillar of cloud thou led them by day, and in a pillar of fire by night, to give them light in the way in which they should go.

yet thou in thy manifold mercies did not forsake them in the wilderness. The pillar of cloud did not depart from over them by day to lead them in the way, neither the pillar of fire by night to show them light, and the way in which