Rabash, Letter 52: And by the exodus from Egypt they received the level of faith…and after Passover, the purifying work begins in preparation for the receiving of the Torah. And when the Torah is dressed in a person’s soul, this is the time of Shavuot, the time of the giving of our Torah.
Until Passover, the period of “the enslavement in Egypt” continues, which means a person feels troubles and blows because of his ego so that he will want to detach himself from it and rise above it to the attribute of bestowal. A person makes new efforts each time through the group, wanting to rise above his ego and be included in the connection. This is the labor in Egypt that continues until its full measure, and then the Light gives a person the power of correction.
But it’s only the ascent above his ego, which the holiday of Passover symbolizes. Then we begin to count 49 days until the holiday of Shavuot, when we detach ourselves from our ego and rise to the level of Bina. The dairy foods we eat in Shavuot symbolize bestowal—a holiday full of Light.
Therefore, in Passover we leave the “left line,” and in Shavuot we receive the beginning of the “right line.” Then we receive the Torah, which means the “middle line.” Then we can connect our ego with the power of the Torah, with the Light we receive from Bina which reforms, and continue to build ourselves.
The holiday of Shavuot seems light and “airy”: We wear white clothes and eat dairy foods; all symbolize bestowal, Light, and the “right line.” A person hasn’t acquired vessels yet; he hasn’t discovered the ego. The first contact with the “right line,” with the Light, isn’t real until we fulfill it in the “middle line,” which we have to build by ourselves. A person takes from the “left line” the parts he can attach to the “right line,” and with the help of the Light, fulfills this connection by receiving a soul, a vessel that will enable him to bestow.
Every holiday we have symbolizes a certain level at which, after having fulfilled the previous stage of development in one line, we move on to the other line, in order to form the third line. Then we dress these three lines in our perception of reality according to the timeline.
From the 3rd part of the Daily Kabbalah Lesson 5/24/12, Writings of Rabash