The connection of Beriyah, Yetzirah and Asiyah with Atzilut at their root in Nekudim.
The single material of Nekudim divides in two stages: essential/secondary first, then control passes. The structural staging is what produces ABYA's eventual integration.
Op. 39 said Nekudim is single material. Op. 40 says how it divides. The chapter is structurally compact but architecturally important. The two-stage division produces the successive state Op. 36 named — the un-integrated cosmos that the breaking will work through.
The two stages are: essential/secondary division first, then control passes. The first stage produces the basic articulations — the distinction between Atzilut and BYA, between the four expansions, between the Sefirot. The second stage is when control passes from the upper articulations to the lower — when the structures become operationally distinct, each running its own portion of the cosmic government.
The technical Klach term for the second stage is SaG (gematria 63) of SaG / BaN (gematria 52) of SaG of SaG* — the recursive expansion-arithmetic that becomes load-bearing in the 288 sparks unit (Op. 54–58). The two-stage staging is the cosmogonic seed of the entire post-Nekudim operational structure.
Op. 41 will explain why the Line cannot fully join the Residue at the outset of Nekudim — the resurrection-archetype. Op. 46 will describe the actual breaking, which is the operational consequence of the two-stage division failing to integrate.