Zeir Anpin, "the small Face," is made of the six broken points of the world of Tohu, from Chesed to Yesod, which the Tikkun joined into a single complete partzuf; it corresponds to the vav of the Name, the letter whose value is six.
His growth fills a large part of Shaar HaKlalim. First conception: three Sefirot contained within three, nine months in the womb of Ima. Then nursing, twenty-four months, through which his "legs" grow, like a child who already has legs but cannot walk before he has nursed. At that stage he has only six extremities, like a vav, with a head of smallness, and his limbs are thin "like the horns of grasshoppers." Finally comes a second conception, to receive the brains of greatness, for a child does not yet have his complete knowledge.
A second conception after nursing? Shaar HaKlalim anticipates your surprise with a verse from Job: "from my flesh I shall see G-d." Just as each night souls rise into Malkhut and are renewed there, "new every morning," so Ima conceives Zeir Anpin and the Nukva a second time and gives them new brains. These brains enter him in stages, which the text compares to the ages set by the Sages: six years and a day, nine years and a day, thirteen years and a day, the age of becoming an adult.
Zeir Anpin receives light from two sides. Through Abba and Ima, who envelop him; and directly, through the hair and beard of Arich Anpin, which come down to his head. In this sense, says Etz Chaim, he is at times higher than Abba and Ima; but since the flow reaches him only through them, in another sense they are greater than he. His own beard has only nine arrangements, where that of Arich Anpin has thirteen.
Cordovero understands the name differently. In the Pardes, Zeir Anpin is "the second concealment," which gathers eight Sefirot, from Chokhmah to Yesod. And under the entry "Zeir Anpin," he reports the view that makes it Tiferet, wonders whether it should rather be seen as Malkhut, and leaves the question open until his commentary on the Idra.
Keep the Ari's way of seeing: even above, growth takes time, and each age has its powers. What is true of Zeir Anpin is the shape of all growth: conception, nourishment, then maturity.
