Whenever God wanted Israel to break up camp and move on, He would send on from its place over the Ark the cloud in which beamed the two sacred letters Yod and He in the direction in which Israel was to march, and the four strips of cloud over the standards would follow. As soon as the priests saw the clouds in motion, they blew the trumpets as a signal for starting, and the winds thereupon from all sides breathed myrrh and frankincense.
Although it was the clouds that gave the signal for taking down and pitching tents, still they always awaited the word of Moses. Before starting the pillar of cloud would contract and stand still before Moses, waiting for him to say: "Rise up, Lord, and let Thine enemies be scattered; and let them that hate Thee flee before Thee," whereupon the pillar of cloud would be set in motion. It was the same when they pitched camp. The pillar of cloud would contract and stand still before Moses, waiting for him to say: "Return, O Lord, unto the many thousands of Israel," whereupon it would expand first over the tribes that belonged to the standard of Judah, and then over the sanctuary, within and without.