Numbers 10:3
And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation. And when they shall blow with them, all the assembly shall assemble themselves to thee at the door of the tabernacle of the congregation.
Numbers 10:3 belongs to a perfectly ordered system God gave for governing Israel, in which trumpet signals communicated directions to the people. Moses gave directions to the sons of Aaron, who marched just behind Moses and Aaron near the sacred ark bearing trumpets, and they signified Moses' directions to the people through the trumpets. Blowing both trumpets together was the appointed signal summoning the whole assembly to Moses at the entrance of the tabernacle of the congregation.
A special signal first called the attention of the people, then certain distinct, clear sounds told them what to do, and there was no confusion of sound in the trumpets. The people knew and understood each sound and moved accordingly, and the clear signal gave them shared direction and orderly movement with no excuse for confusion in movement. At Sinai this order meant the trumpet blast was the signal for the whole camp to set forward in order, with the tabernacle borne in the midst and each tribe in its appointed position under its own standard, while all eyes watched anxiously to see in what direction the cloud would lead them.
The head officer of each company gave definite directions so that none who gave attention was left ignorant of what to do, and the signal was so clear that failure to know what was required was no excuse. All had the same opportunity to learn and the same opportunity for instruction as others, so not knowing from inattention was as great a sin as transgressing after hearing. Failure to comply was punished with death. The same God of order is as particular now as then, and the perfect order instituted in the days of Moses teaches lessons of order and organization today.