Matsya Purana — Genealogy of Kaśyapa: Ādityas
सहस्रशिरसां कद्रूः सहस्रं चापि सुव्रत प्रधानास्तेषु विख्याताः षड्विंशतिर् अरिंदम //
sahasraśirasāṃ kadrūḥ sahasraṃ cāpi suvrata pradhānāsteṣu vikhyātāḥ ṣaḍviṃśatir ariṃdama //
Kadrū, O noble one, gave birth to a thousand serpent-lords of a thousand heads; among them, O subduer of foes, twenty-six are famed as the principal ones.
It does not describe Pralaya directly; it contributes to the creation-era genealogical mapping by enumerating Kadrū’s Nāga progeny and identifying the principal serpent-lords.
Indirectly, it supports the Purāṇic model of righteous governance and social memory: kings and householders are urged to preserve lineage-knowledge (vaṃśa) and sacred history, which the Matsya Purana treats as part of dharma and cultural continuity.
No explicit Vāstu or ritual rule appears in this verse; its focus is genealogical—identifying the principal Nāgas within a larger cosmological catalogue.