Exodus 33:8-11

8Whenever Moses went out to the tent, all the people would rise and stand at the entrances to their tents and watch Moses until he went in.

9As soon as Moses went into the tent, the column of smoke would come down and stay at the entrance to the tent while the Lord spoke with Moses.

10When all the people saw the column of smoke standing at the entrance to the tent, they would all bow with their faces touching the ground at the entrance to their own tents.

11The Lord would speak to Moses personally, as a man speaks to his friend. Then Moses would come back to the camp, but his assistant, Joshua, son of Nun, stayed inside the tent.