The Torah, “Leviticus,”10:4 to 10:5: And Moses summoned Mishael and Elzaphan, the sons of Aaron’s uncle Uzziel, and said to them, “Draw near; carry your kinsmen from within the Sanctuary, to the outside of the camp. So they approached and carried them with their tunics to the outside of the camp, as Moses had spoken.
If I am on a certain level, I cannot rise to the next level or descend (I cannot perform a spiritual ascent or descent) before I perform certain actions.
Nadav and Avihu found themselves in the Holy of Holies on the level of the adhesion of the soul with the Creator, on the level of bestowal (Holiness and Holy symbolize the attribute of bestowal). In order to ascend to that level, they had to use their big ego, sanctify it, and transform it from reception to bestowal. When they found themselves in the Holy of Holies and tried to perform this action, they did not manage to do it. Therefore, instead of the fire of Holiness (the revelation of the Light of Hochma, in order to bestow), the opposite happened.
Therefore, the two vessels, the two attributes (Nadav and Avihu) fell, which means that they remained on the same level, the level of the dead. In every desire there are levels of the still, vegetative, animate, and human. In that case, the attributes fell from the human level to the level of the still nature so that they should be corrected.
What is the meaning of “carry your kinsmen from within the Sanctuary, to the outside of the camp?” A camp refers to the gradual unity of the souls. The two attributes Nadav and Avihu fell to such a level on which they were not connected to anything and are therefore called dead. They must be corrected anew from their state. Therefore, they are taken out of there.
But this isn’t the first example of certain attributes that are removed from a certain level. For example, the great priest who died was taken out of the Holy of Holies on Yom Kippur, when a rope was tied to his foot in advance, since it was certain that his thoughts wouldn’t be pure. But he couldn’t restrain himself since he wanted to reveal the Creator so much and kept on with it.
He used to enter the Holy of Holies on Yom Kippur, which means that he ascended to such a high level that his body had to be taken out of there with a rope tied to his foot, while Nadav and Avihu were taken out by iron rods.
Iron, copper, silver, and gold are four materials in our world that are correlated with spiritual events. A whole section is dedicated to these relations.
From KabTV’s “Secrets of the Eternal Book” 1/22/14