Matsya Purana — The Maheshvara Vow: Śiva-Caturdaśī Vrata
ब्रह्महत्यादिकं किंचिद् यदत्रामुत्र वा कृतम् पितृभिर्भ्रातृभिर्वापि तत्सर्वं नाशमाप्नुयात् //
brahmahatyādikaṃ kiṃcid yadatrāmutra vā kṛtam pitṛbhirbhrātṛbhirvāpi tatsarvaṃ nāśamāpnuyāt //
Any sin—beginning with brahmahatyā, the slaying of a brāhmaṇa—whether committed here (in this life) or in another existence, whether by one’s fathers/ancestors or even by one’s brothers, all of it would be destroyed, completely annulled.
It does not describe cosmic Pralaya; it uses the idea of “destruction” (nāśa) in an ethical sense—complete dissolution of sins through purifying merit or expiation.
It supports the Purāṇic ethic that a householder (and by extension a king responsible for public dharma) should perform purifying rites and meritorious acts that can annul even severe sins affecting one’s family line, emphasizing responsibility toward ancestors and kin.
No Vāstu or iconographic rule is stated; the ritual takeaway is the doctrine of powerful purification—acts of merit/atonement can eradicate even grave sins attributed to oneself or close relations.