“In a more mystical sense, it is true, the ‘asiluth represents the name or the names of God, as has been shown in the preceding chapter. This theosophic conception was preserved in Gerona. Creation can subsist only to the extent that the name of God is engraved in it.
The revelation of the name is the actual revelation, and the Torah is not merely a conglomeration of the names of God, but, in its very essence, nothing but this one name itself. This doctrine, which transmuted an originally magical tradition into a strictly mystical one, was clearly expressed for the first time in Gerona, and from there reached the author of the Zohar.
Light-mysticism for the emanation and language-mysticism for the divine name remain the two principal means by which the world of the sefiroth could be described.
For Nahmanides, the ten sefiroth are the “inwardness” of the letters. The beginning and the end of the Torah together form, according to a mystical pun, the “heart,” of creation; in terms of gematria, the traditional mysticism of numbers the numerical value of the word (thirty-two) also indicates the thirty-two paths of wisdom active in it.
This “heart” is nothing other than the “will” of God itself, which maintains the creation as long as it acts in it. For it becomes the Nothing, (the inversion of the same two letters), as soon as the will reverses its direction and brings all things back to their original essentiality, “like someone who draws in his breath.”
But this return of all things to their proprietor is also their return to the mystical pure Nothingness. The primordial beginning of creation consisted in the emergence of hokhmah from the infinite plenitude of the “supreme crown” or the will, in an act of limitation, simsum, in which the all-embracing divine kabhod was restricted.
This restriction of the light at first produced a darkness, into which there flowed the clear light of hokhmah. We thus find in Nahmanides the oldest form of the doctrine of a self-contraction of God at creation, which, however, is not a contraction of the ‘en-sof itself, as taught by later kabbalists, but of the first sefirah.”
Gershom Scholem, Origins of the Kabbalah, pp. 448-9.