Class One. We need walls to protect us in two ways: 1) Protect Klipa from coming in and getting more life than what Hashem allotted for it. [Klipa exists to give us more meaningful free will and the additional life it leaches adds to fulfilling it’s purpose of challenging our free will] 2) Prevent Klipa from getting in to the Pnimiyus of Ohr and Ratzon and getting any of it. When Moshiach comes there will be פרזות no need for walls, but then there will still be חומת אש.
Class Two. This class explains the Avoda of all these levels. Walls are Torah (in general, and specifically) 1) To keep not good out: Lo Taseh, 2) To keep the good in: Asei. Breaking down the walls once Klipa is all gone: The idea that Mitzvos are infinite. The wall of fire continues: There’s black fire because of the fire in the world, then there’s the never changing white fire, this is the third level. This will shine Liasid.
