Tzimtzum — The First Restriction

The Ari's own original act, prior to and underlying every masach that follows it: Ein Sof's withdrawal of its own infinite light from a single point, to make an empty, receivable space possible at all. Every subsequent masach, on Ashlag's reading, repeats the SHAPE of that first restriction at a smaller, personal scale — a person choosing not to receive directly is doing, deliberately and locally, what Ein Sof did once, globally, to make creation possible in the first place.

⭐⭐ WHY THE MASACH IS NOT A LATER, LESSER ADD-ON TO LURIANIC DOCTRINE. Ashlag is explicit that the masach mechanism is not his own invention laid over Luria — it is Luria's own tzimtzum, applied consistently at every rung of the ladder rather than treated as a one-time cosmological event that happened only once, long ago.