So Moses stood in the gate of the camp and said: “Whoever is for the Lord, [let him come] to me!” And all the sons of Levi gathered around him.
He said to them: “So said the Lord, the God of Israel: ‘Let every man place his sword upon his thigh and pass back and forth from one gate to the other in the camp, and let every man kill his brother, every man his friend, every man his kinsman.'”
“…every man kill his brother, every man his friend, every man his kinsman” stands for ridding oneself of the properties, habits, desires, hopes, and memories that one cherishes the most, i.e. letting go of the core of one’s entire life and universe. One has to part with these notions forever, “shut them down,” internally restrict them, and then gradually correct other qualities.
An appeal “Whoever is for the Lord, [let him come] to me!” stands for “Whoever is for the pure bestowal…”
“And all the sons of Levi gathered around him” refers to people or to certain human qualities that have to “stand out” (become obvious) from the point of view of the internal part of the Torah.
Question: Then, why did the sons of Levi take part in the creation of the golden calf?
Answer: It happened because there was no Moses, no illumination of the Upper Light on Malchut. When the Light influences Malchut, the properties that are ingrained in it rise. In other words, the Levites approach Moses; whereas, if the Light doesn’t descend to Malchut, the Levites stay under the influence of Malchut’s power of egoism. The Levites have no choice of their own.
It applies solely to Mose’s governance that descends through every part of the system to the people. That’s why Aaron, the Cohens, and the Levites are only “adapters” that connect Moses with the people.
From KabTV’s “Secrets of the Eternal Book” 9/11/13