Exodus 40:36-38

Whenever the cloud was taken up from above the tabernacle, the children of Israel would go onward in all their journeys. But if the cloud was not taken up, then they did not journey till the day that it was taken up. For the cloud of the LORD was above the tabernacle by day, and fire was over it by night, in the sight of all the house of Israel, throughout all their journeys.