Matsya Purana — Devayānī–Śarmiṣṭhā Dialogue: Yayāti’s Transgression
वयो दास्यति ते पुत्रो यः स राजा भविष्यति आयुष्मान्कीर्तिमांश्चैव बह्वपत्यस् तथैव च //
vayo dāsyati te putro yaḥ sa rājā bhaviṣyati āyuṣmānkīrtimāṃścaiva bahvapatyas tathaiva ca //
Your son will sustain you in old age; he will become king, long-lived and renowned, and likewise blessed with many offspring.
This verse does not discuss pralaya; it focuses on royal succession and auspicious qualities promised to a future king.
It highlights putra-dharma—an ideal son supports his parents in old age—and links that virtue with kṣatriya ideals: rightful kingship, longevity, fame, and continuation of lineage through many offspring.
No Vāstu, temple architecture, or ritual procedure is mentioned; the verse is a genealogical blessing/prophecy about kingship and progeny.