Kalach Pitchei Chokhmah and Tanya

Both texts accept tzimtzum as essential to creation. Text 1 emphasizes the 'empty space' (חלל) as a receptacle (בית קיבול) where worlds emerge from reshimu (residue), with the Ein Sof's surrounding aspect (סובב) remaining unchanged. Text 2 emphasizes how multiple successive tzimtzumim allow divine life-force to descend sufficiently to clothe even inanimate matter, focusing on the gradual attenuation of vitality (חיות מועט בימאד מאד). Text 1 focuses on spatial accommodation and immanence (ממלא); Text 2 emphasizes the mechanism of descent and divine indwelling in the lowest created forms. They differ in analytical focus rather than substantive position on tzimtzum's function.