Exodus 40:34-38

Then the cloud covered the tent of meeting, and the glory of the LORD filled the tabernacle. Moses could not enter the tent of meeting because the cloud had settled on it, and the glory of the LORD filled the tabernacle. In all the travels of the Israelites, whenever the cloud lifted from above the tabernacle, they would set out; but if the cloud did not lift, they did not set out—until the day it lifted. So the cloud of the LORD was over the tabernacle by day, and fire was in the cloud by night, in the sight of all the Israelites during all their travels.