When the time comes for these souls to enter this world, it is possible for one, two, three, or ten, etc. sparks to come at once and in the same generation, if they are from the same root. More specifically, it is possible for two sparks to come into this world at one time, one from the right spring and one from the left spring of that root, or for five sparks to come at the same time and they are the first five joints of the five fingers of the right hand. Alternatively, the first ten joints of the ten fingers of the right and left hands and the like.

...it is possible for two sparks to come into this world at one time...

Thus, you can find in a single generation many sparks that are from the level of the tendons which are close to each other. This is why you should not be surprised to find Rabbi Akiva and Akavia ben Mehalelel [living simultaneously], or to find in the generation of Amoraim Abaye, Rami bar Chamma, and Rav Dimi from Nehardea, even though they are [all] from the root of Cain, from the left shoulder of Adam, as we will later explain.

There is another reason for what we have been speaking of and that is, when the Shechina went into exile amongst the kelipot, all the souls of the righteous went with it. Depending upon the level of the mitzvahs performed by a righteous person from that root, and the time it is done, one or more sparks will be able to leave the kelipot and ascend into this world. This is even though the sparks are not near one another in the root. It all depends upon the time and the mitzvahs that the righteous person from that root performs.

There is also another related matter: Adam had a nefesh from Asiya, a ruach from Yetzira, a neshama from Beriya, and above this a NR"N from Atzilut, from the Nukva of Zeir Anpin, from Zeir Anpin, and from Imma [respectively].

The three from the world of Atzilut are called zehira ila’a of Adam, and are explained in the Zohar in the Sitrei Torah [Secrets of the Torah] section. (Kedoshim 83a)

Before Cain and Abel were born, Adam sinned and the zehira ila’a was removed from him...

Before Cain and Abel were born, Adam sinned and the zehira ila’a was removed from him, that is the three portions we mentioned from Atzilut. In this manner, the decree of G‑d was fulfilled: "On the day you eat from it you shall surely die" - for the three portions of Atzilut were removed from him and there is no harsher death than this.1

When Cain and Abel were born, the nefesh of Atzilut which had been removed from Adam was divided between Cain and Abel. Later we will explain, G‑d willing, the gilgul of Cain from the level of nefesh of Atzilut that he merited, how it reincarnated and went to Keinan and Mehalelel, until it reincarnated into Nadab and Abihu, the sons of Aaron, "the two parts of one body2", as mentioned in the Zohar Pinchas and Acharei Mot.

This is what is written, "There were men who were unclean by nefesh adam [the dead body of man]" (Num. 9:6) - literally nefesh Adam [the soul of Adam], for it is talking about Nadab and Abihu, as the Sages say, who were on the level of the nefesh of Adam. After that, it went to Pinchas when he killed Zimri, as the Zohar mentions, and as we will discuss later, G‑d willing. We will also clarify how Cain and Abel took the nefesh of Atzilut of Adam to rectify it, after he sinned with the tree of knowledge of good and evil.

[Translation and commentary by Perets Auerbach.]