The hierarchical division of the people of Israel began from the time of Moses. After he received the Torah and brought the people into the wilderness, his father-in-law Jethro taught him how to correctly organize the hierarchy of the people.
Before then people always were in a circle, gathered around Mount Sinai and feeling that they were equals. In the Exodus from Egypt, they needed to work in three lines, correctly integrating their egoistic desires, arranged according to a hierarchy with an altruistic intent that had to be circular. This was because even though it was directed toward the Creator, it was derived from the center of the circle. How was it possible to integrate these two things? For this, Jethro gave Moses a method for correctly handling the people.
People must yearn to become round in their intention but not in their mutual compliance with movements toward the Creator. The equality can be only in intent because from the start the desires are not ours. They are given to each one of us from above.
Jethro suggested dividing the people into tens, hundreds, thousands, and so forth. Each of the twelve tribes went to its camp. All kinds of unifications and connections between them were prohibited. For example, it was not allowed for them to marry others from another tribe. Each tribe had to keep to itself, but simultaneously, they had to advance together.
The correct combination between individuals and a single unity was revealed through choosing ministers for tens, hundreds, and thousands, while the High Priest was chosen from the tribe of Levi, which was composed of Levites and Cohens only.
In this way Jethro established and arranged hierarchical work with the ego because he had been a servant of Pharaoh. However, because he precisely knew the entire system of Pharaoh he could be an intermediary between Pharaoh and Moses.
From KabTV’s “Secrets of the Eternal Book” 5/21/14