The Shulchan Aruch (Even HaEzer 1:9) rules that a person is allowed to marry many wives, but that the Sages advised against marrying more than four women. I want to understand how this can be reconciled with the statement of Chazal that a person’s zivug (destined mate) is announced 40 days before conception. Does this mean that only one zivug for a man is announced? Or do they announce more than one zivug for him? Also, how does this work out with the words of the Mekubalim about the concept of “soul roots”, that a husband and wife come from the same soul root – is this only true about one’s first wife, or would it also apply to other wives he marries [even during the lifetime of the first wife]…?
At the root, each person has his zivug (destined mate). However, afterwards, a division took place in which one soul became divided into many different parts. For example, there are five names of the soul, the Nefesh, Ruach, Neshamah, Chayah and Yechidah. At first all of these levels of the soul were attached together, and later they became divided from each other. It is possible for the “Nefesh” part of one’s soul to be in one person’s body, while the “Ruach” part of his soul [which had been previously attached with his Nefesh] is in another person’s body. There is also a further subdivision of the soul, because each of the five parts of the soul contains the levels of Nefesh, Ruach, Neshamah, Chayah and Yechidah, so there is a “Yechidah” part of one’s “Nefesh”, and etc.
Therefore, it is possible for one’s true zivug to be found in several women. One’s “Nefesh” can be found in Leah, while his “Ruach” can be found in Rachel, etc. If a person is meritorious enough, he merits that “his zivug comes to him”, so that even if his zivug only contains a part of his soul, he can merit to join with the other parts of his soul, either through the concept of “ibbur” (lit. “impregnating” – when another’s soul becomes added onto his own), or through gaining a “nitzotz”, a “spark”, of another’s soul. This concept is explained about in the Shaar HaGilgulim [of the Arizal], and others.
[Joining with] the actual root of the soul is called [joining with] one’s “first zivug”, while [joining with] all other divided parts of one’s soul are called [joining with] the “second zivug”, an additional soul-mate.