Matsya Purana — Mandāra-Saptamī Vrata
एवमभ्यर्च्य तत्सर्वं दद्याद्वेदविदे पुनः भुञ्जीतातैललवणं वाग्यतः प्राङ्मुखो गृही //
evamabhyarcya tatsarvaṃ dadyādvedavide punaḥ bhuñjītātailalavaṇaṃ vāgyataḥ prāṅmukho gṛhī //
Having thus duly worshipped, the householder should again give all of that to a knower of the Veda. Then, facing east and restraining his speech, he should eat—avoiding oil and salt.
This verse does not address Pralaya directly; it focuses on post-worship discipline—charity to a Veda-knower and restrained, purified eating—reflecting dharmic conduct rather than cosmology.
It prescribes a householder’s orthodox routine: after completing worship, one should honor Vedic learning through dāna (gift/feeding to a vedavid) and practice self-control (silence, east-facing posture, simple food), modeling the ethical restraint expected in both domestic and royal life.
The ritual significance is in regulated upacāra: gifting the worship-related provisions to a qualified Veda-knower and observing austerity (no oil/salt, silence, east-facing). While not Vastu Shastra, the east-facing orientation aligns with common ritual-direction norms in Puranic practice.