Read Exodus 13:21 Using Other Translations
And the LORD went before them by day in a pillar of a cloud, to lead them the way; and by night in a pillar of fire, to give them light; to go by day and night:
And the LORD went before them by day in a pillar of cloud to lead them along the way, and by night in a pillar of fire to give them light, that they might travel by day and by night.
The LORD went ahead of them. He guided them during the day with a pillar of cloud, and he provided light at night with a pillar of fire. This allowed them to travel by day or by night.