I see the beginning in Tzaddi as fish hook extends through its final into the corrosive waters of Mem, wherein dwells the fish of Nun. Ayin draws up the fish, which then becomes Zain as Sword of Din striking into the womb of Binah, and the world is divided into systole and diastole. "Running and returning" is a process of restlessness, which is wickedness, for if allowed to continue brings the misfortune of "The Lord of the Gates of Matter" as "supreme principle" (the second God as apparent reality, layer upon layer of a weeping onion) when it is in effect only a reflection of the Void. That is to say, Ayin = Ain , but only in the sense that it conceals Ain in this formula. And yet herein is also concealed a true path of return.
See also the 26th Tunnel of Set, A'ano'in for the rampage of the Dionysian sabbath that is created light by which the Eye projects when it does not "return to the place".