On the day that the Tabernacle was set up, the cloud covered the Tabernacle, the Tent of the Pact; and in the evening it rested over the Tabernacle in the likeness of fire until morning. It was always so: the cloud covered it, appearing as fire by night.
And whenever the cloud lifted from the Tent, the Israelites would set out accordingly; and at the spot where the cloud settled, there the Israelites would make camp. At a command of the Lord the Israelites broke camp, and at a command of the Lord they made camp: they remained encamped as long as the cloud stayed over the Tabernacle. When the cloud lingered over the Tabernacle many days, the Israelites observed the Lord's mandate and did not journey on. At such times as the cloud rested over the Tabernacle for but a few days, they remained encamped at a command of the Lord, and broke camp at a command of the Lord.
And at such times as the cloud stayed from evening until morning, they broke camp as soon as the cloud lifted in the morning. Day or night, whenever the cloud lifted, they would break camp. Whether it was two days or a month or a year--however long the cloud lingered over the Tabernacle--the Israelites remained encamped and did not set out; only when it lifted did they break camp. On a sign from the Lord they made camp and on a sign from the Lord they broke camp; they observed the Lord's mandate at the Lord's bidding through Moses.
The Lord spoke to Moses, saying: Have two silver trumpets made; make them of hammered work. They shall serve you to summon the community and to set the divisions in motion. When both are blown in long blasts, the whole community shall assemble before you at the entrance of the Tent of Meeting; and if only one is blown, the chieftains, heads of Israel's contingents, shall assemble before you. But when you sound short blasts, the divisions encamped on the east shall move forward; and when you sound short blasts a second time, those encamped on the south shall move forward. Thus short blasts shall be blown for setting them in motion, while to convoke the congregation you shall blow long blasts, not short ones. The trumpets shall be blown by Aaron's sons, the priests; they shall be for you an institution for all time throughout the ages.
When you are at war in your land against an aggressor who attacks you, you shall sound short blasts on the trumpets, that you may be remembered before the Lord your God and be delivered from your enemies. And on your joyous occasions--your fixed festivals and new moon days--you shall sound the trumpets over your burnt offerings and your sacrifices of well-being. They shall be a reminder of you before your God: I, the Lord, am your God.