We have already explained that Cain and Abel took the nefesh of Atzilut that had been in Adam. The following is the explanation:

As is known, all the worlds are connected to each other. Thus, after man rectifies the world of Asiya, he can ascend to the world of Yetzira, and keep ascending even to Atzilut, as it says in the Zohar at the beginning of the portion Mishpatim. "If he merits more, they give it to him." This is, as already explained in previous discussions, only true of a ‘new soul’, which can ascend from world to world [in one lifetime], as mentioned there.

The worlds were made by G‑d, from the Torah, for the souls.

The worlds were made by G‑d, from the Torah, for the souls. "The Holy One blessed be He and the Torah and Israel are one." (Zohar II) The worlds follow the order of the Divine name outlined in the Torah and according to the soul roots. Just as the letters of the name are one and inter-connected, so are all souls and all worlds. It follows that the souls are able to ascend from rung to rung. Each time someone ascends, it is a new stage in revealing the oneness.

Thus we find that all the worlds are connected, and the lower one serves as a throne for the higher one.1There are levels of souls that are only able to rectify the level of the nefesh of Asiya while some can reach Yetzira, others Beriya, and some can even reach as high as Atzilut. However, they are a small minority among all the soul-roots.

This ability exists, though, only among the soul-roots of Cain and Abel, since they are new souls in some respects as explained, and they therefore can merit to rectify and receive even the nefesh of Atzilut, but no more. However, the rest of the souls are called ‘old souls’, and they cannot receive the nefesh of Atzilut - if only they would merit to receive the neshama of Beriya!

The soul-roots of Cain and Abel have two levels.

The soul-roots of Cain and Abel have two levels. The first is the level of the souls of Cain and Abel themselves, souls that fell off and remain in the worlds of BY"A [Beriya-Yetzira-Asiya] only. There is a second and higher level, the portion of Adam himself which he gave to his sons Cain and Abel as an inheritance. It seems to me that it is a spark from the father himself put into the nefesh of the son to guide them.

This is part of why the child must honor the parent. The honor fuels that spark to manifest in the person and help him fully. This is the main inheritance. Other aspects of inheritance such as finances and objects are actually branches of this.

The second level is drawn from all worlds, that is, from the nefesh of Asiya to the nefesh of Atzilut. Thus, any person whose soul is from this second level is on a great level, because he can rectify from the nefesh of Asiya until the nefesh of Atzilut the first time he enters the world. Through this he can merit to receive the nefesh of Atzilut. Not, however, the ruach or the neshama of Atzilut, since they are not completely new souls, as mentioned.

I have already explained in previous discussions that regarding this second rung which Adam gave to Cain and Abel as an inheritance, there are two levels, ohr makif and ohr penimi. All the souls of this level, as already explained, for example, Issachar, Rabbi Akiva, and Hezekiah - all of them are from the ohr hapenimi of this level. So too was Elijah the Prophet z"l from the ohr hapenimi of this level. Later, Nadab and Abihu, who were from the ohr makif of the nefesh of Atzilut of this second level, came to him in ibur [an added soul] .