Matsya Purana — Dhruva as Cosmic Pivot: Motions of Sun–Moon–Planets
शक्रेण पक्षाश्छिन्ना वै पर्वतानां महौजसा कामगानां समृद्धानां भूतानां नाशमिच्छताम् //
śakreṇa pakṣāśchinnā vai parvatānāṃ mahaujasā kāmagānāṃ samṛddhānāṃ bhūtānāṃ nāśamicchatām //
Indeed, mighty Śakra (Indra) cut off the wings of the mountains—those powerful, prosperous beings that moved at will—because they sought the destruction of living creatures.
It does not describe Pralaya directly; it explains a stabilizing cosmic act—Indra restrains the roaming, destructive mountains—supporting order in the world rather than dissolution.
The verse models the dharmic duty of governance: powerful forces that endanger beings must be restrained for loka-saṅgraha (public safety and social order), a principle applicable to righteous kingship and household responsibility.
No direct Vāstu or ritual rule is stated, but the underlying idea is spatial stability: mountains becoming fixed supports the notion of a settled, orderly landscape—an implied prerequisite for towns, temples, and sacred sites to be established.