Baal HaSulam, “Introduction to The Book of Zohar,” Item 11: For the body, which is the will to receive for itself, extends from its root in the Thought of Creation, through the system of the impure worlds, as it is written, “and [from] a wild donkey a man will be born” (“Job” 11, 12). And he remains under the authority of that system for the first thirteen years, which is the time of corruption.
And by engaging in Mitzvot from thirteen years of age onwards, in order to bestow contentment upon his Maker, he begins to purify the will to receive for himself imprinted in him, and slowly turns it to be in order to bestow. By that he extends a holy soul from its root in the thought of creation. And it passes through the system of the pure worlds and dresses in the body. This is the period of correction.
The “13 years” that Baal HaSulam speaks of refers to something that has nothing to do with our world. In our world a person is not considered a grownup at 13-years-old, but rather a baby who is still operated by his natural instincts. We don’t expect him to act rationally and to understand what he does or to deeply clarify his actions. Accordingly, there are no laws by which he has to abide.
But in spirituality it’s a totally different concept, and it refers to a person who has to complete his work on the previous levels. He yearns for the goal and wants to reach it by the different means he was given, and constantly acquires the negative vessels in contrast to his positive vessels. But time after time he discovers the greater dominance of the system of ABYA of impurity which he overcomes and doesn’t let it rule. But then it appears even stronger than before, and once again a person doesn’t let it rule…
A person actually advances by two systems, since he wouldn’t be able to distinguish the system of impurity without the system of Holiness. So it is actually the system of impurity that manages him along the way.
Thus we are under the influence of the system of impurity, the shell, during the first phase of our advancement to spirituality. The spiritual desire to receive in order to receive constantly grows in these worlds, and a person feels its growing dominance. He doesn’t just feel it, but rather feels it with regard to connection and mutual guarantee. All our discernments are with regard to the one vessel, the reconnection into one man as it was before the breaking of the vessels. This is what we are attracted to in our correction and accordingly receive different hardenings of the heart, which means that the Reshimot (reminiscences) are revealed one by one in heavier forms of the intention of in order to receive.
This continues until we reach the state of “delighting the Creator.” When a person is able to delight the Creator it’s a sign of the next state, which means that he is already in some level of equivalence of form with Him by being under the influence of the systems of the worlds of BYA of holiness.
From the 2nd part of the Daily Kabbalah Lesson 01/01/14, Writings of Baal HaSulam