The Soul of the Soul as the Hebrew letters has a close correspondence to the notion of Veda in the Vedic tradition, where the true Veda is not the Vedas that are chanted by the priests but the supernal cognitions of  the rishis or seers. The true Veda is comprised of the individual "sounds" which the seers "hear" in the supernal "world" and which they also "see." Veda is called "shruti," meaning that which is heard and the etymology of the term "Veda" relates to knowledge through "sight," i.e., direct and unmediated cognition in the supernal state in which seer and seen are one. In both the Hebrew and Sanskrit traditions, the "letters" are considered to be of transcendental origin, and the letters of the human alphabet are mere shadows of them. The Rig Veda says, "richo akshare parame vyoman," which can be rendered either, "the hymns [reside' in the alphabet in the transcendental space," or "the hymns [reside] in that which does not fall - the eternal unchanging - the transcendental [non-localized and non-temporal] space."

This etymology of "veda" corresponds to the Platonic notion of "ideas," the Greek "idea" being correlative with the Sanskrit "vidya," meaning knowledge by "sight." The analogy of the cave in the Republic makes it clear that the ideas are actually  "seen" in a supernal sense by those who leave the cave of gross consciousness and see in the light of the "sun" of transcendental awareness.

This Platonic notion was later imported into Christian mystical theology by Augustine, who saw the "ideas" as being in the "mind" of the Creator, through which God creates.

Shalom, Salaam, Shanti,

Tom

Yakov Leib comments:
Very interesting correspondence. I should also point out that the Neshama Le'Neshama level of interpretation -- the "Soul of the Soul" -- refers not only to an hermeneutical understanding of the Hebrew letters themselves, but also to the very deepest level of meaning even beyond them -- that is, literally, the "Soul of the soul" which is, of course, God himself, or Ayn Sof.

Levels of Meaning in Holy Scripture: Vedic
Dr. Thomas Hickey