[Insert standard Meredith warning here.]
Earlier, I suggested that the Cloud of Glory that rested over the Tabernacle might be a Priestly version of the pillar that guided the Israelites through the wilderness, which appeared as a cloud of smoke by day (when the smoke obscured the fiery center) and a fire by night (when darkness obscured the smoke). A passage from this week's parsha seems to support this notion (though its authorship is contested):
On the day that the Tabernacle was set up, the cloud covered the Tabernacle, the Tent of Testimony, and in the evening it hovered over the Tabernacle in the likeness of fire until morning. It was always so: The cloud covered it [the Tabernacle], and it appeared as fire at night. And whenever the cloud rose from the tent, the Israelites would travel, and wherever the cloud rested, the Israelites would encamp (Numbers 9:15-18).