80. Concerning Back to Back
Panim and Achor (face and back).
Panim means reception of bounty or bestowal of bounty.
Negation is called Achoraim (posterior), meaning neither receiving nor giving.
Hence, in the beginning of the work, one is in a state of Achor be Achor (back to back) because he still has the vessels of the desire to receive. If he extends abundance into these Kelim, he could blemish the Light, since he is considered opposite in value, since the Lights come from the root, and the root only bestows.
For this reason, the lower ones use the Kelim of Ima, called Achoraim, meaning that they do not want to receive, so as not to blemish. And the Emanator, too, does not bestow upon them, for the above reason, that the Lights guard themselves so the lower ones do not blemish them. This is why it is called Achor be Achor.
To explain what is written in several places, that “wherever there is a deficiency, there is suction for the Klipa.” We might say that the reason for it is that this place is still not clear of Aviut. Otherwise, the Light would have illuminated in perfection, since the Upper Light never stops. If there is a place that is corrected with a Masach, the Upper Light is immediately gripped there. And since there is a place of deficiency, meaning absence of the Upper Light, there is certainly a discernment of Aviut (thickness/will to receive), whose entire grip is in the will to receive.