Exodus 40:36-38

40:36 But when the cloud was lifted up from the tabernacle, the Israelites would set out on all their journeys; 40:37 but if the cloud was not lifted up, then they would not journey further until the day it was lifted up. 40:38 For the cloud of the Lord was on the tabernacle by day, but fire would be on it at night, in plain view of all the house of Israel, throughout all their journeys.