Coupling while striking with the Light happens at the screen, which is standing at the Partzuf’s head. Afterward, it descends from there onto the place in the desires that are possible to be fulfilled. These are not geometric places, located on one side or another, but these are desires.
At the head, coupling while striking happens with the Light and the decision is made that some desires can be fulfilled, while others cannot. All of these desires are gathered together and a calculation is performed on them. Similar to how there are numerous places in the human organism where the decisions are made in the head and then they are activated.
Let’s say that an order to make the blood vessels narrower has been issued. Now, this order goes to any place where there are blood vessels in the body, and it is to only them and the special muscles located at the vessel walls that constrict them. One effect of the decision applies to all of these vessels.
In the same way the action takes place in the Partzuf’s head, which results in an order being issued. The head is the place which sends the orders. An order is formulated from below, above in the head and it controls the implementation of the action bottom-up in the body of the spiritual Partzuf.
This action is done by that same Light, which has made the decision in the head: what to receive, how much and how, with what intention, to bestow at the expense of what, with the help of what vessels, desires, with what connection between them.
Here, it is like in a musical scale, there are no more than the eight notes “Do-Re-Mi-Fa-So-La-Ti-Do”, while the order is issued thanks to their connection, the chord, a combination of various particular actions uniting together.
That is why the Light, which is being disseminated in the head, has a special form of a Light’s order. And it is the one to implement this action in the body and everything happens there according to the force, coming from the head, and activating the nervous and other systems. And this is how the body implements an order.
If only the GE (Galgalta ve Eynaim) are activated in the head, then in the body, in each of its parts and cells, in each desire, only the GE are being activated due to the combination of orders, which the head has taken considering the thousands of various conditions: onto what depth of the desire to disseminate this action (Aviut), relative to what, and so on.
It seems to us that coupling while striking is a simple collision, like the strike of the pendulum, but this is not so. It is a million times more complicated and full of details than the orders of the brain, which the human organism is regulated by.
From the 3rd part of the Daily Kabbalah Lesson 2/21/12, The Study of The Ten Sefirot