The Zohar, “Introduction of The Zohar,” Chapter “BeLaila De Kala (Night of the Bride),” Item 130: “The correction of Yesod is Brit Milah (circumcision). Hence, it is said that the existence of the covenant is called “the work of our hands,” for we separate the Orlah (foreskin) from Yesod through the work of our hands. But this only concerns the period up to the end of correction.”
Until the end of correction (Gmar Tikkun) we operate within the ten Sefirot of our soul. First of all, we must cut Malchut off, meaning to exclude from operation the desire that cannot be corrected. Moreover, we cut desires until Yesod, and we only work with those Kelim that lay above it, to the extent of our ability to incorporate them into Bina.
This is the “union of circumcision”: We deactivate the desires that cannot be used until Gmar Tikkun. They will only be corrected at the end of correction. But we can receive Light for the sake of bestowal in all the other Kelim (vessels) from Keter to Yesod.
…as it is said: “From my flesh I shall see the Creator.” Specifically “from my flesh,” because every time man signs the covenant of this union, he sees the Creator there.
“From my flesh” means from the receiving Kelim. The bestowing Kelim are located above, until the middle of Tifferet, and the receiving Kelim that are called “flesh” and “skin” are located under them.
It is only possible to see the Creator, that is the Light of Hochma (Wisdom), in the receiving Kelim, but only on the level of the “flesh” (Basar). We do not even touch the “skin.” In other words, we stop at the third stage (flesh, meat, or Behina Gimel), and we do not engage the fourth stage (skin, Behina Dalet).
From the 1st part of the Daily Kabbalah Lesson 11/17/10, “Hakdama, Laila de Kale (The Night of the Bride)”
And The Lord Appeared To Him By The Oaks Of Mamre