Part 13 · Chapter 106

Thus it is found that there are three aspects of thirteen in the three heads of Arich Anpin, namely the skull (Galgalta), the Avira, and the Mocha. And corresponding to them, three aspects of thirteen-thirteen are mentioned in Idra Rabba. These are they: on page 128, side B, it says, "This skull, its whiteness illuminated to thirteen sides..."; and on page 129, side A, it says, "Thirteen locks of hair stand from this side and from that side of the skull..."; and in the Idra of Ha'azinu, page 288, side B, it says, "Because this hidden wisdom that is within it is divided three times into four-four, and it is the Atik that includes them..."