Matsya Purana — Intermediate Dissolution
यः शरीराद् अभिध्याय सिसृक्षुर्विविधं जगत् अप एव ससर्जादौ तासु वीर्यम् अवासृजत् //
yaḥ śarīrād abhidhyāya sisṛkṣurvividhaṃ jagat apa eva sasarjādau tāsu vīryam avāsṛjat //
He who, contemplating from within his own being and wishing to bring forth the manifold universe, first created the Waters; and into those waters he then deposited his generative potency.
It describes the opening movement of creation (sarga): before differentiated worlds appear, the primeval Waters are produced first, and the divine “seed” (vīrya) is placed in them as the causal power from which further creation unfolds.
By analogy, it models purposeful creation: a king or householder should act after clear intention (abhidhyāna) and establish a stable foundation first—like “waters” as the base—before expanding projects such as governance, family duties, or charitable works.
Direct Vāstu rules are not stated, but the principle is foundational: rites and constructions begin by establishing a purified base element (often water in ritual purification) before “installing” potency—mirroring how consecration (pratiṣṭhā) places sacred power into a prepared locus.