Exodus 13:7, 20-22

Unleavened bread shall be eaten seven days; and there shall no leavened bread be seen with thee, neither shall there be leaven seen with thee in all thy quarters.

And they took their journey from Succoth, and encamped in Etham, in the edge of the wilderness. 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: he took not away the pillar of the cloud by day, nor the pillar of fire by night, from before the people.