When desires for spirituality, for the goal of creation, for the Creator, appear in us, it means that a black point, which is part of Malchut has awoken in us. But this black point is surrounded by the desire to receive, the ego, on all sides.
If we manage to raise our black point out of the ego so that it will be above the ego and the ego will remain totally below, which means that we will be attracted to the Creator although the ego pulls us in the opposite direction, then this point will be disconnected from the ego. I don’t take my ego into account in my inclination to the Creator. This disconnection is called Tzimtzum (restriction).
If we connect all our points, a big black point is created. It is black because it feels darkness. It wants to yearn for the Creator, but it doesn’t know how to do so. All our points are above, connected to one another, and our whole big ego is left below pulling us downwards.
If we attain a critical mass of our yearning for the Creator in contrast to the ego, which means that we reach a sufficiently strong tension, then under the influence of the Surrounding Light, we disconnect from the ego and perform Tzimtzum Aleph (first restriction). This is called the Exodus from Egypt, disconnection from our desire to receive.
From the Daily Kabbalah Lesson 4/11/14, Talk About Dissemination: Questions & Answers with Dr. Laitman