The case is that the Sephiroth, just as they are from Above to Below - in their sequence: Kether, Hokhmah, Binah, Gedulah, Gevurah, Tifereth, Netzach, Hod, Yesod, Malkuth - so they are from Below to Above: Kether, Hokhmah, etc. How is this possible? Kether is in Malkuth, Hokhmah is in Yesod, Binah is in Hod, Gedulah is in Netzach, Gevurah is in Tifereth, Tifereth is in Gevurah, Netzach is in Gedulah, Hod is in Binah, Yesod is in Hokhmah, and Malkuth is in Kether.

In order that this matter not be too difficult, we will compare it to a fitting example. It is like the resemblance of the sun's shining that extends from its source and strikes a polished mirror, then its light turns and returns to its source. This is called, among the scholars, the "light that turns." So we, when we wish to allude in these Gates to this secret, we call it by the name the "turning light," or the "returning light," for the whole meaning is one.

Our intention is to say that the reality - just like the resemblance of the light mentioned above, so it is with the likeness of the Emanations, for the Sephiroth are Emanations and they extend from Above to Below in straight succession. With the Sephiroth, this is what we call, in these Gates, the "direct light," and it means that they extend in this order.

Thus the Light works: its position is in Malkuth, and it returns to its source, up to Kether, and there is its position. This is "their end is fastened in their beginning and their beginning in their end" [Sefer Yetzirah 1:7], because Kether dwells in Malkuth and Malkuth in Kether. And not only this, but the Malkuth that is in Kether also returns and descends below! And it behaves in the same was as the first light, until light is turned into light, and light into light, without end. All is fastened, end into beginning and beginning into end. This is the secret that exists in "direct," and this is the secret that exists in "returning," one through the secret of the direct light and the other through the secret of the returning light, like so:

Thus the meaning is alluded to in the secret of the letter Aleph, which is Yod in the beginning and Yod in the end, like so:

And the secret is Yod in the beginning and Yod in the end because the source of the Light of the world is Yod. From there the Light emanates. Sometimes the Yod is above, and it is the direct light, the source, the beginning; sometimes the Yod is below, and it is the returning light, a source to the light that returns. And so it is that "their end is fastened in their beginning and their beginning in their end."

This is the interpretation of Rabbi Simeon bar Yohai in his explanation of this teaching, in the Tikkunim [Tikkunei Zohar 21]: "Regarding the structure, it is ten in the beginning of Aleph and it is ten in the end, about which it is said, 'declaring the end from the beginning' [Isaiah 46:10]. It is Yod, Heh, Vav, Heh, comprising the ten Sephiroth, which is that meant by 'their end is fasatened in their beginning and their beginning in their end.'"

The Will of G-d is that, just as there is the illumination of the return of the Light from Malkuth, so is the return of the Light from Yesod, and from Hod - and so it is for all of them. Just as there is the direct light from Kether, so it is from Hokhmah, and from Binah, and from Hesed, because each Sephirah is a source to all that are below it, and each Sephirah is a mirror which the Supernal Light strikes, and the Light returns, until, in this manner, the illuminations ascend, dwell, and return infinitely!

While the casual reader may understand with his intellect, when will he take to heart that which is alluded to?

Pardes Rimmonim, Gate 15
Rabbi Moshe Cordovero