Sefer Etz Chaim and Tanya

Both texts affirm klipat-nogah contains mixed holy and impure elements that fell during shevirat hakelim. Text 1 emphasizes klipat-nogah's structural role as garments (levushim) separating kelipot and enabling mitzva performance through its mixed nature (טוב ורע). Text 2 emphasizes klipat-nogah's defiling contamination (טומאת) of divine intellectual faculties (chokhma-bina-daat) that fell there. Text 1 stresses functional utility and separation; Text 2 stresses spiritual contamination and impurity. Same concept, different theological emphasis.