Masach — The Screen

The mechanism, in Ashlag's system, by which a vessel (kli) that wishes to receive light from above may do so without falling back into the will-to-receive-for-itself that caused the very first restriction. A masach placed against incoming light blocks reception outright — and it is that act of blocking, done with the intention to give rather than to take, that produces ohr chozer (reflected light), which in turn draws down exactly as much of the original light as the vessel has earned the right to receive lishma, "for Her sake."

⭐⭐⭐ THE MECHANISM THIS WHOLE WING TESTS. Without a masach, a vessel can only ever receive in its own default, self-directed way — which is Malkhut's own native condition (ms-malchut-only) — and no amount of light arriving from above changes that. The masach is not a wall that keeps light out; it is the ONLY thing that lets light in on different terms than the vessel's own unaltered desire, which is Ashlag's answer to the question this wing exists to ask: what must a person actually DO to receive at any of the nine levels above Malkhut's default one.