Numbers 10:5

When ye blow an alarm, then the camps that lie on the east parts shall go forward.

The alarm blast was the command for the camps lying on the east to break camp and go forward, and in the departure from Sinai the eastern camps moved out first. The alarm belonged to an ordered system for the journey in which the trumpets gave distinct sounds with known, understood meanings, so the tribes could move in order under their standards without confusion. When the ark was to move, the sons of Aaron, who marched near the ark behind Moses and Aaron, received directions from Moses and announced them by trumpet, first sounding a special signal to call the people to attention and then certain sounds telling how to move, with the alarm calling the east to go forward. At the same time the head officer of each company gave definite directions so that no one who gave attention was left ignorant of what to do.

At the signal the whole camp set forward in order, with the tabernacle borne in the midst and each tribe marching in its appointed position in order under its own standard bearing the sign of its father's tribe. The direction of that march from Sinai was fixed by the leading of the cloud, which moved toward the east toward black and desolate mountain masses, and watching it filled many hearts with anxiety, sadness, and doubt. Because there was no confusion of sound in the trumpets, there was no excuse for confusion of movement. The people could know what movement was required and were responsible for obeying, and all had the same opportunity to learn the signals.

Failure to comply brought death, and claimed ignorance was willing ignorance counted as guilty as disobedience. The same God of order who arranged this system still requires attention, discipline, and united action, for he is a God of peace and not of confusion.