Sefer Etz Chaim and Tanya

Both texts affirm the kav as the channel through which Ein-Sof light enters the chalal and constricts/limits infinity into finite sefirot. Text 1 emphasizes the kav's role in preventing merger with Ein-Sof (to maintain distinction between 'natzal and 'meatzil') and enabling measured influx through ten concentric circles. Text 2 emphasizes the kav as embodied tzimtzum creating gevul (boundary/limitation) within souls, framing it as divine contraction itself. Text 1 focuses on the kav's structural/mechanistic function in maintaining separation; Text 2 treats the kav as the very means of tzimtzum creating divine contraction. Both compatible but different focal points.