Now we will explain the left arm and wing in which is the root of Cain, from which you can understand the right of Abel.

Cain is (from) the left wing limb of Adam

As said, Cain is [from] the left wing limb of Adam, in which there are three levels - flesh, tendons, and bones. In all five parzufim of BY"A [Beriya-Yetzira-Asiya], there is a root of Cain in the left arm and left shoulder. But there is no level of wing. However, in the five partzufim of Atzilut there is the level of shoulder, [comprised of] flesh, tendons, and bones, and the level of wing.

Thus we find that all roots from this second level of Cain have the level of shoulder with flesh, tendons, and bones, as well as the level of wing which comes out from them. For they are [as] the ‘feathers’ that emanate out of the shoulder limb. This is only in Atzilut and not BY"A, which only has the shoulder. We explained the left shoulder previously.

The left wing...has three thousand feathers...

Now, we will explain the wing. The left wing in which the roots of the soul of Cain reach has three thousand feathers - a thousand large, a thousand medium-size, and a thousand small ones. Within each feather there are 150 hairs, which are the level of soul-sparks. For each feather, there is one hole in the shoulder limb in which the feather is wedged and from which it grows.

As well, every feather has at its upper end that is stuck into the hole - a level of blood that is absorbed within it. At the other end, above the head there is a small section of tube that has no hair. Beyond this, hairs sprout from both sides until the end of the feather, of which there are large long hairs, and small short hairs.

The small hairs are the soul-sparks of the small children who died young. There are many levels among them, for none of the small hairs are the same length, as is understandable. Likewise, there are many levels among the large hairs, and the length of the hair determines the number of years of a particular soul in this world.

Know that the feather itself is a much higher level than the hole from which it sprouts, and the blood that is absorbed within it and the beginning of the tubing that is stuck in the hole. It is also a much higher level than the hairs that grow from both sides, and the long hairs that come out from the small ones.

...each feather has K"N [150] soul-sparks...

Also know that each feather has K"N [150] soul-sparks, which is the gematria of ChNF/kanaf [wing]. This number is based upon the name KYN/Cain, which contains KN.1 However, the right wing is the level of Abel, and it divides in another way based upon his name, as follows.

Each feather divides into Hei [five] sections, and each section incorporates Lamed Beit [thirty-two] sparks, which is HBL/Hevel/Abel: H times LB. There are also 150 sparks, just as is the case with the sparks of Cain, except that the 150 sparks of Cain in each feather itself subdivide into 150. However, in the case of the sparks of Abel, which divide into five sections, each section contains [only] thirty-two sparks. This is the only difference between Cain and Abel [in regards to the configuration of the energies in the wing-level].

Even though five times thirty-two equals a hundred and sixty? Just as KYN/Cain with the Y/yud equals a hundred and sixty?! Here also, as said, Y is the makif aspect that is not included...

Cain comes from the left-gevura side whose nature is to constrict and divide. (Tefilas Keriyas HaShema u'Shemone Esrei) Therefore, they separate again into 150.

[Translation and commentary by Perets Auerbach.]