The opening lines of our parasha describe a pillar of fire and cloud hovering above the nation and acting as a signal to the Israelites to lead them on their desert trek. We wonder as to exactly how they worked. Did these pillars of cloud/fire lead the Israelite nation throughout the 40 years in the desert? Did they simply serve a role of signalling the direction of travel or did the clouds serve a different function? Chazal talk about sven "clouds of glory" protecting Israel and flattening the path ahead! What is the source for that? And why were "cloud" and "fire" the substances that were appropriate for the task?
Read the shiur here.