Matsya Purana — The Rohiṇī–Candraśayana Vow
शूद्रो ऽपि परया भक्त्या पाषण्डालापवर्जितः सोमाय वरदायाथ विष्णवे च नमो नमः //
śūdro 'pi parayā bhaktyā pāṣaṇḍālāpavarjitaḥ somāya varadāyātha viṣṇave ca namo namaḥ //
Even a Śūdra, if endowed with supreme devotion and free from the speech and ways of heretical sectarians, may offer repeated salutations—to Soma, to the boon-giving Lord, and to Viṣṇu.
This verse is not about pralaya; it focuses on devotional eligibility and purity—teaching that sincere bhakti, free from impious influences, is spiritually effective regardless of social category.
It supports the dharmic duty of maintaining pure religious practice: householders (and kings as guardians of dharma) should encourage sincere devotion and discourage corrupting, irreverent, or disruptive sectarian conduct (pāṣaṇḍa-ālāpa).
Ritually, it emphasizes proper worship through repeated salutations (namo namaḥ) to revered deities; no specific Vāstu or temple-construction rule is stated in this verse.