Every spiritual object is divided into internal and external parts, and this structure remains throughout all rungs of the spiritual ladder. Moreover, the internal parts of all rungs are connected with each other, while all external parts are interconnected as well. The internal desires are called “root,” “soul,” and “body” (Shoresh, Neshama, and Guf), and each one is located within the other. Besides that, there are external desires which are called “garments” (Levush) and “house” (Heichal). The body of the upper spiritual object passes the Light to the root of the lower object which also has the internal desires: “root,” “soul,” and “body.” Its “garments” and “house” are located outside and they are not taken into account. This is because desires cannot connect with each other if they lack the screen (Masach).
Only the screen creates connection. Therefore, beginning from the Second Restriction (Tzimtzum Bet), the calculation is performed only for the internal desires, that is, the ones that are covered by the screen. After all, how can one connect with others in a desire which is not under the power of the anti-egoistic screen?
After the breaking of the common soul, we’re like a sack of nuts that have to exist together. The nuts bump against each other, but nothing more. A person receives a possibility to connect with other souls only to the degree that he acquires the internal desires. The outermost internal part of the Upper One connects with the innermost part of the lower one according to the similarity of their properties.