Matsya Purana — Vishnu’s Battle with Mathana
स पपाताथ दैत्येन्द्रः क्षयकाले ऽचलो यथा तस्मिन्निपतिते भूमौ दानवे वीर्यशालिनि //
sa papātātha daityendraḥ kṣayakāle 'calo yathā tasminnipatite bhūmau dānave vīryaśālini //
Then the lord of the Daityas fell—like a mountain collapsing at the end of time. When that mighty, valorous Dānava crashed down upon the earth, he lay struck down.
It uses pralaya-language as a simile—“kṣaya-kāla” (time of dissolution)—to convey the overwhelming, world-shaking force of the Daitya leader’s fall, not to describe an actual cosmic pralaya event here.
Indirectly, it reinforces a Purāṇic ethical theme: even the most powerful rulers (here, an Asura-king) are subject to downfall; kingship and strength are impermanent, so rule should be grounded in dharma rather than pride.
No Vāstu or ritual procedure is taught in this verse; the only technical imagery is the comparison to an “acala” (mountain), employed as a poetic measure of mass and impact.