The original Israelite civilization offered no evidence of having had a mystical initiatory tradition of any sort. Indeed, prominent Kabbalah scholars such as Gershom Scholem have famously insisted that there was no mysticism at all in biblical Israel. It is this unaccounted-for peculiarity that launched a painstaking investigation, the results of which are recounted in this book. The research sought to foreground what has been dubbed the "second channel" within the Pentateuch and the book of Joshua, a narrative stratum hypothesized to contain ideational and some concrete information regarding the conjectured missing initiatory system of the priests of the First Temple. The Sod Hypothesis substantiates that the authors of the Pentateuch and the book of Joshua intended to communicate to future generations the fact of the existence of their otherwise concealed esoteric system. The temple priests in Jerusalem (Kingdom of Judea, or Judah, the "Southern Kingdom") who created this communication wanted it to survive any unforeseen calamity, perhaps after they had witnessed the destruction of the Kingdom of Israel (the "Northern Kingdom") by the Assyrians in 720 BCE. With that in mind, they encrypted their communication in and through the specific form that the Pentateuch and the book of Joshua took. Their thinking likely was that the otherwise confusing, obscure esoteric material captivatingly presented in semihistorical settings and in magnificent, spellbinding literary-narrative forms would ensure the work's long-term survival. The priestly communication was not coded in a way that would have required a special key or "code" (since then the task of recovery by future readers could prove to be unfeasible and thus not serve the ultimate aims of the authors). Rather, it was embedded by way of literary-allegorical and symbolic-esoteric means. To assure a concise and specific information transfer, an elaborate system of linguistic-semiotic-esoteric correspondences was developed; thus, if the intended recipient(s) managed to grasp at least one vital element of the system, the rest would unfold, constructed out of logical inferences involved in the emerging system of deliberately fashioned correspondences. As to who might have been the intended specific recipients (here, paraphrasing Derrida): "the secret" was made public yet without revealing it. The Hexateuch endeavors to create both coded esoteric instructions to individual initiates, partially via parabolic projection onto Exodus and other narratives, and also, simultaneously, a national exoteric program of transformation of an entire people into what would be called "a nation of priests and a holy people," in effect, a nation of initiates and spiritual aspirants-a feat quite unparalleled in history. The concealed inner-core esoteric knowledge concerns a mystical transformation of consciousness of a would-be Israelite priestly initiate who thereby gains access to the national deity, with the latter's awesome powers. Even the fact of the existence of the priestly mystical-initiatory system, let alone its contents, was a secret. KEYWORDS: Pentateuch; Torah; Hexateuch; Judaism; Hebrew Bible; Old Testament; ancient Israel; early antiquity; First Temple; Israelite; priesthood; religion; communication; secrecy; initiation; sod; religious experience; cognitive; consciousness; Jewish mysticism; kabbalah; altered states; esoteric; noetic; literary; figuration; nonliteral; phenomenology; intention; intension; hyle; noema; doxa; episteme; poiesis; deixis; semiotic; transitivity; hyponoia; metaphor; allegory; allegoresis; metalepsis; emergence; God; YHWH; Elohim; sublime; categorization; de dicto; de re; tree of knowledge; tree of life; Eden; mysterium tremendum; identity; complex systems"