On the eighth day, the son, the new level that was born out of the seven Sefirot, totally detaches from the mother. But in order to exist in the future, he cannot use the flesh of his foreskin, his greatest and most egoistic desires.
He has to resist them and not allow himself to use them, as it says: “cut off the edge of your heart,”i.e., desires, because we can only use our most egoistic desires after the end of correction.
First all of humanity undergoes correction by including only the desires of Keter, Hochma, Bina, Hesed, Gevura, Tifferet, Netzach, and Hod. And Yesod, the last Sefira of the Lights that descend from Above through which the Light enters Malchut (the created being) has to be cut off, to be restricted.
This means that we also use the Sefira of Yesod but it is restricted so that it will not convey all the Light in it to Malchut. This is important!
In addition, circumcision symbolizes the connection between all the Sefirot and Malchut that is fulfilled through Yesod. This is the reason that it is called a covenant (in Hebrew). This connection cannot exist without the circumcision of Yesod, without the restriction of its dominance over Malchut.
The term circumcision refers to the fact that we remove the greatest desires, the heart of stone (Lev HaEven) that cannot be corrected into love and bestowal. However, all the other desires can be used. Therefore it is actually after the circumcision that a person is considered Jewish (Yehudi) stemming from the Hebrew word “Yihud” (unity, connection) since now he can connect with the Creator.
Question: Why is the flesh of the foreskin thrown to the sand?
Answer: It is because you cannot use it; it is equal to corporeal dust.
The flesh of the foreskin symbolizes the greatest, cruelest egoistic desires that you cannot use in order to bestow, but at the same time, these desires are very valuable and so although they burn in you, you now equate their value to dust.
Question: Will there be a time when we will not have to circumcise the newborn?
Answer: At the end of correction! Then there will be no more prohibitions, no commandments, because all the commandments are partial corrections of the attribute of love and bestowal. If you correct everything, there will be no limitations left in any of the desires! You will begin to use them freely since you will have the intention of in order to bestow on top of every desire.
From KabTV’s “Secrets of the Eternal Book” 2/12/14