Numbers 9:20-22

Sometimes the cloud was a few days over the tabernacle, and according to the command of the LORD they remained in camp; then according to the command of the LORD they set out. And sometimes the cloud remained from evening until morning. And when the cloud lifted in the morning, they set out, or if it continued for a day and a night, when the cloud lifted they set out. Whether it was two days, or a month, or a longer time, that the cloud continued over the tabernacle, abiding there, the people of Israel remained in camp and did not set out, but when it lifted they set out.