In order for the property of the Light to penetrate desire, a special process of descent takes place. First of all, desire is imparted with a sensation that it is opposite to the Light. As a result, it cannot bear itself and performs a restriction (Tzimzum).
Afterwards, desire concludes: “I need a screen (Masach).” In other words, it needs a chance to equalize itself with the Light by performing an autonomous act. This means that it will indeed be detached from the Creator and face Him as the guest before the host. Even though the guest receives nothing from the host, he still feels that he is opposite and suffers from it.
I don’t need the feast that the host has prepared for me; I reject it. But the host still keeps asking me to taste from his table and laments my not accepting his gifts. Seeing that, I do accept them, being fully aware that I am doing it solely to delight him.
Thus, being opposite, the Light and the creature are detached from each other. The Light wishes to fulfill the creature (1), whereas the creature pushes it away (2). But eventually, when the Light returns and “begs” (3), the creature, as if doing a favor, agrees to receive from it (4). This reception is regarded as bestowal. Thereby, their relationship develops.
This is the development by way of the screen. The creature presents itself as a place of desire, but this desire is covered by the screen. It is as though desire installs a “divider” atop and decides: No matter how much Light comes in (1), the first thing I will do is push it back (2). But the Light still pressures me (3), so in that case I calculate (?) how much of it I am able to receive. I let the right amount in and receive it as a “treat” (4).
The calculation becomes an additional factor: How much am I able to receive in order to bestow to the host as much pleasure as he wants to give me? And this calculation makes me a human (Adam) since thereby, I claim my autonomy in complete detachment from the host and act as he does. He gives to me, and I to him. Or, as it is described in the Song of Songs: “I am for my Beloved as my Beloved is for me.”
Acting this way, the created being arrives at a corrected state, and this kind of reception makes it a spiritual vessel. Why a “vessel”? Because it can receive the Light. Why “spiritual”? Because it is equal to the Creator and bestows like He does.
From the 3rd part of the Daily Kabbalah Lesson 3/4/2011, “Explanation to the Article, Preface to the Wisdom of Kabbalah”