When Zeir Anpin and Nukva are complete they are ready for Interior and Exterior coupling.
When Z"A and Nukva are complete (post-Nesirah), they are ready for Interior and Exterior coupling. Two coupling-modes that distinguish kinds of cosmic flow.
Op. 136 specifies the coupling-readiness condition. Z"A and Nukva must be complete — fully constructed, post-Nesirah, in Face-to-Face position — before Coupling can occur in its full operational form. The chapter introduces the Interior/Exterior distinction.
Interior coupling is what occurs at the cosmic-anatomical interior. Z"A's interior radiates into Nukva's interior; the coupling produces internal effects that operate at the deepest concealed levels of the cosmic government.
Exterior coupling is what occurs at the cosmic-anatomical exterior. Z"A's exterior turns to face Nukva's exterior; the coupling produces external effects that operate at the visible operational level — the level at which the lower creations receive cosmic governance.
Both coupling-modes are required. Interior coupling alone would produce concealed effects without operational visibility. Exterior coupling alone would produce visible effects without depth. Together they produce a complete cosmic-operational flow that has both concealed depth and operational visibility.
Op. 137 (branches contained — the Coupling's contents). Op. 138 (the eight-stage Coupling order — the closing operational mechanism).