If we do not feel pleasure from being purified of past baggage, then we do not really want to be purified. After all, we are still yearning for pleasures that do not belong to the Creator, to bestowal, rather we want to be filled egotistically.
Getting rid of egoistic intention, from receiving for our own sake, is called the work of purification. To do this, I must jump into the upper light, as if into the water, and completely immerse myself in it, so that the light will act on me and purify me.
This is how it happens at every new degree. When we ascend the degrees of attainment of the Creator, coming closer to Him, every degree begins with the work of purifying ourselves. This is the first stage. The second stage already is holiness when we are already in connection with the upper light.
But first, we need to get rid of our egoism, purify ourselves with the help of the upper light as if we are plunging into the water, into the sea. Once we are purified, we can put on clean clothes, that is, restriction, screen, and reflected light.
From the 1st part of the Daily Kabbalah Lesson 11/9/21, Writings of Baal HaSulam, Shamati #54 “The Purpose of the Work-1”