Binah
Understanding — anatomical left (left pillar)
Binah — the womb of comprehension that takes the seed-flash of Chokhmah and develops it into structured understanding. The classical image is the upper river dividing into many channels: Chokhmah is the wellspring, Binah is the elaboration. As the supernal Mother (Imma) she gives birth to the seven lower sefirot. In body-projection Binah sits at the left side of the head. In Chabad psychology she is the discursive reasoning that takes a flash and writes it out, lecture by lecture, until insight becomes knowable.
Point 3 of 10 in Kabbalah — Tree of Life (Adam Kadmon)
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Zohar I.16a (primary_canonical)
Zohar I.16a (Vilna folio pagination) develops the expansion and differentiation of the primordial point into understanding, the basis for the Binah-as-womb/comprehension image. The passage does not prescribe a bodily location.
Cordovero, Pardes Rimonim, Gate 23 (the Names of the Sefirot) (primary_canonical)
Pardes Rimonim, Gate 23, treats the names and qualities of the ten sefirot, including Binah's formative/comprehending role. The gate supports the diagram's sefirotic terminology; its internal section numbering differs by edition.