Exodus 40:34-38

Then the cloud covered the tent of meeting, and the glory of the LORD filled the tabernacle. And Moses was not able to enter into the tent of meeting, because the cloud abode thereon, and the glory of the LORD filled the tabernacle. And when the cloud was taken up from over the tabernacle, the children of Israel went onward, throughout all their journeys: but if the cloud were not taken up, then they journeyed not till the day that it was taken up. For the cloud of the LORD was upon the tabernacle by day, and there was fire therein by night, in the sight of all the house of Israel, throughout all their journeys.