Numbers 9:16-18
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.