The Torah, “Exodus” (Ki Tissa), 33:21-33:23: And the Lord said: “Behold, there is a place with Me, and you shall stand on the rock. And it shall be that when My glory passes by, I will place you into the cleft of the rock, and I will cover you with My hand until I have passed by. Then I will remove My hand, and you will see My back but My face shall not be seen.”
“And you will see My back” means that the lower system can connect only with the posterior (Achoraim) of the upper system.
“The rock” are the discernments in a person’s ego that begin to acquire the right attributes and a person can hide in them.
The expression “and I will cover you with My hand” refers to a special concealment when a person can look at the upper through its posterior and connect to it, but in a state of concealment on the part of the Upper. This connection isn’t fulfilled as a result of bestowal from Above, but as a result of the right preparation on the part of a person. The Creator does everything else.
Thus, all our work is called “God’s work” (Avodat Hashem), while a person does the preparation. If a person is ready, the Creator fulfills his request.
From KabTV’s “Secrets of the Eternal Book” 9/16/13