Completion of Zeir Anpin during Pregnancy, Suckling and Maturity.
Temporal anchors: 9 months pregnancy, 24-month subperiod for HYM (suckling), 13 years for full suckling, maturity from 13 years and a day.
Op. 121 specifies temporal anchors for Z"A's three-stage construction. The numbers parallel human-developmental timelines but apply to cosmic-operational time.
9 months pregnancy: Z"A is hidden inside Imma for nine cosmic months — the gestational period during which the Partzuf is built but not yet operationally visible.
24-month subperiod for HYM (Hesed-Yesod-Malchut, the bottom three Sefirot of Z"A's Mochin): a specific cosmic period during which these Sefirot complete their initial structural form.
13 years for full suckling: Z"A continues to suckle from Imma for the equivalent of a human's first 13 years (the period before bar mitzvah).
Maturity from 13 years and a day: the cosmic-operational analogue of bar mitzvah — Z"A operates with full Mental Powers from this point.
The principle behind the temporal anchors: a stage's duration is determined by gradation intrinsic to the process, not by arbitrary specification. The cosmic-operational time is what the structural-cosmogonic process requires.
Op. 128 (regular oscillation between First and Second Maturity — Shabbat as the rhythmic instance of higher-maturity intensity). The temporal anchors run through the closing operational chapters.