Baal HaSulam, Beit Shaar HaKavanot (The Gateway of Intentions), Item 87: Sefira Keter with the Light of Nefesh is called the state of Ibur [embryo] of each degree, which has not yet scrutinized its “body” and is wholly located in the Klipat Noga, where the good is mixed with the evil.
Only the root is corrected in it for now, not the body itself, and that is why the entire body is called the “skin” for now. But when it reaches the state of Yenika [breastfeeding] and receives Kli de Hochma, into which the Light of Ruach clothes itself, it then receives the “body.”
In the state of “embryo” (Ibur), the good is mixed with the evil, and we do not know how to differentiate it. However, in the state of “breastfeeding” (Yenika, drawing of sustenance), we are already beginning to distinguish between the good and evil and to use the good desires. Due to our clarifications, we grow, and that is why this state is called “breastfeeding.”
It is not a material infant who is born and changes his place, coming out of the mother to the outside. A spiritual “embryo” and an “infant” that receives sustenance are different kinds of connection between the upper one and the lower one.
If I cannot scrutinize anything by myself and the upper one does it for me, then this state is called an “embryo.” If I participate in the clarifications myself and differentiate the good from evil, using the good, then this is “breastfeeding.”
If I clarify the Klipat Noga (the Noga shell) so as to make a “shield” out of it from the three impure Klipot (shells), turning the selected evil into the “skin” that protects me, then I can begin to build myself, choosing from the mixture of good and bad desires.
This is a special mixture since in it the qualities of the Creator and the creature are intermixed. It is precisely out of this that I have to build something new: an independent man (Adam, meaning “similar” to the Creator).
From the 3rd part of the Daily Kabbalah Lesson 12/20/10, Beit Shaar HaKavanot