Matsya Purana — Ritual Procedure and Merit of Donating the Ratnācala
ब्रह्महत्यादिकं किंचिद् यदत्रामुत्र वा कृतम् तत्सर्वं नाशमायाति गिरिर्वज्रहतो यथा //
brahmahatyādikaṃ kiṃcid yadatrāmutra vā kṛtam tatsarvaṃ nāśamāyāti girirvajrahato yathā //
Whatever sin—beginning with brahmin-slaying—has been committed, whether in this world or in the next, all of it perishes, just as a mountain is shattered when struck by a thunderbolt (vajra).
It uses a cosmic-style simile (a thunderbolt shattering a mountain) to describe moral dissolution: even the heaviest sins can be utterly destroyed through powerful purificatory means; it is about the dissolution of pāpa rather than cosmic pralaya.
It supports the dharmic principle that rulers and householders must seek prāyaścitta for wrongdoing—especially grave offenses—so that social order and personal karma are purified rather than carried forward into future consequences.
No Vāstu or temple-architecture rule is stated; the ritual takeaway is the asserted efficacy of prāyaścitta (atonement/purificatory rites) to annihilate even severe sins.