Sefer Etz Chaim and Tanya

Both texts address the kav and its relationship to the chalal and tzimtzum. Text 1 (Etz Chaim) emphasizes the kav as a descending structure (יושר) that penetrates and fills the empty space (החלל), flowing through circular forms (עגולים) from above downward, with specific measurements of extension. Text 2 (Tanya) emphasizes the kav as a garment (מלובש) of divine light compressed through tzimtzum, focusing on the metaphysical status of souls rather than spatial extension. Text 1 prioritizes the geometric-structural aspect of kav filling chalal; Text 2 prioritizes the ontological function of kav as channeling contracted divinity. Both accept kav's necessity in chalal, but differ in what they stress about its mechanism and purpose.