The Study of the Ten Sefirot, Part 15, Item 139: When Mochin of Aba ve Ima enter ZA, Aba has Hochma-Bina and Hesed-Gevura, and opposite them Ima has the same. When falling to ZA, Hochma and Hesed de Aba attach to Hochma and Hesed de Ima and clothe in his NHY. And Bina and Gevura de Aba attach to Bina and Gevura de Ima in her NHY. Thus AVI regroup to MA and BON.
Initially, the Partzuf Aba has Hochma and Hesed, Bina and Gevura. The same is true for Ima. After that the process resembles genetics: Hochma and Hesed de Aba and Hochma and Hesed de Ima unite together and form MA de AVI. Bina and Gevura de Aba and Bina and Gevura de Ima unite together and form BON de AVI.
The resulting formations relate to one another like ZA and Malchut. As a result of these spiritual forces, we observe this process in our world in virtually everything: Some parts stem from the male organism, others from the female, they unite together, and make a new body.
The consequence of this process manifests in myriad phenomena and all sorts of connections on all levels: the still, vegetative, and animate. Meanwhile, The Study of the Ten Sefirot explains this process on the “human” level, the level of souls.
Moreover, ZA himself has parts of MA and BON, just as Nukva has MA and BON since there cannot exist a Partzuf that doesn’t contain both parts, MA and BON. Accordingly, there cannot be an organism which consists of only the male part (MA) or the female part (BON), but everyone must include both the male and the female components, for the Light cannot exist without the vessel (desire), nor can the vessel (desire) exist without the Light.
From the 3rd part of the Daily Kabbalah Lesson 10/12/10, Talmud Eser Sefirot