“This קְלִפָּה (qelipah), shell… is thin and corresponds to the bran of wheat, for here it sticks to the wheat and cannot be separated from there without grinding it in the mill-stones, which are correspond to the grinding molar in a man’s jaw, with which matters of Torah have to be ground until they are as fine flour. And in a sieve, which is the lips, the waste matter, which is the bran of Torah, is sorted out until the Halakhah is as pure fine flour. At that time, the heart and the brain and all those parts of the body through which the soul spreads, take that and the soul lives on it just as the body lives on things from this world. One against the other God has set (Ecclesiastes 7:14)—just as food for the body, so food for the soul, as is written: Come, partake of my bread (Proverbs 9:5).
And this shell, is like the shell that sticks to the kernel of the nut, for when the nut is soft the shell separates from the kernel without difficulty, but when the nut is dry, it is difficult for man to remove it from there, and the difficult problem still remains. For this reason the blessed Holy One commanded man to return [in repentance] during his youth, before the evil impulse makes him old, as is written: Before a gray head you shall rise (Leviticus 19:32)—before your own old age. And this shell, is fire, about which is written: [And after the fire,] a sound of minute stillness (1 Kings 19:12). [Another shell: darkness over the] deep (Genesis 1:2)—the space that is in the nut about which is written: [And after the fire,] a sound of minute stillness (1 Kings 19:12), for this is where the King comes: [And I saw, and, look, a storm wind was coming from the north, a great cloud,] and fire flashing, and radiance all round it, and from within it like the appearance of חַשְׁמַל (ḥashmal), amber, from within the fire (Ezekiel 1:4)….
And all the people of the world on the outside know not how they eat nor do they know their secret, but the sages that are inside do know and they take from them. For the esophagus cannot be examined from the outside, for they do not know, but on the inside they do know and take until it enters the mill and is pulverized and cooked [cf. BT Behorot 45a; Berakhot 61a]. And the liver takes everything, as we had learnt, but from those offerings by fire issue forth stages that take before the liver. And what are they? They are the molar which eat and grind the sacrifices. Therefore, on the destruction of the Temple, it is written: And the maids who grind grow idle, for they are now few (Ecclesiastes 12:3). These are the first to grind….
Netsaḥ and Hod are the two halves of a body, like two twins, which is why they are called skies (Psalms 78:23). The two of them together are וו (vav, vav) of וֵשֶׁט (veshet), esophagus, from the left side, and they are the two molar teeth from the right side [cf. Exodus 30:36: And שָׁחַקְתָ (shaḥaqta), you shall pound it to fine powder. שְׁחָקִים (Sheḥaqim), skies, and שָׁחַקְתָ (shaḥaqta), you shall pound it to fine powder, share the root שָׁחַקְ (shaḥaq) ‘(to) powder’]….
And from the side of וֵשֶׁט (veshet), esophagus [before which there is grinding in the teeth it is said]: The people would שָׁטוּ (shatu), go about, and gather it (Numbers 11:8). It—the collection of decisions in Mishnah. שָׁטוּ (Shatu), go about [is an anagram of וֵשֶׁט (veshet), esophagus]. And grind it between millstones or pound it in a pestle and cook it in a cauldron and make it into cakes (ibid.). It follows that whoever brings out words of Torah, must grind them in his teeth in order to express words that are called שָׁלֵם (shalem), complete. But as for the others that are scorned, these words are swallowed when eaten greedily, without being ground in their molars and their teeth about them it is written: The meat was still between their teeth, it had not yet been chewed, when the wrath of YHWH flared against the people [i.e., the motley throng] (Numbers 11:33). From the root of him who said: Let me gulp down some of this red red stuff, for I am famished (Genesis 25:30) [עָיֵף (ayef), famished, is numerically equivalent to קַיִן (Qayin), Cain, who is the root of Esau]” (Zohar 3:226b–235a, Ra’aya Meheimna Pineḥas).