Numbers 9:16-20

That is how it continued to be; the cloud covered it, and at night it looked like fire. Whenever the cloud lifted from above the tent, the Israelites set out; wherever the cloud settled, the Israelites encamped. At the LORD’s command the Israelites set out, and at his command they encamped. As long as the cloud stayed over the tabernacle, they remained in camp. When the cloud remained over the tabernacle a long time, the Israelites obeyed the LORD’s order and did not set out. Sometimes the cloud was over the tabernacle only a few days; at the LORD’s command they would encamp, and then at his command they would set out.