Matsya Purana — The Dialogue of Kacha and Devayani: Dharma
एवं ज्ञात्वा विजानीहि यद्ब्रवीमि तपोधन व्रतस्थे नियमोपेते यथा वर्ताम्यहं त्वयि //
evaṃ jñātvā vijānīhi yadbravīmi tapodhana vratasthe niyamopete yathā vartāmyahaṃ tvayi //
Knowing thus, understand well what I declare, O treasure of austerity: as you stand firm in your vow and are endowed with disciplined observances, so do I conduct myself toward you accordingly.
It frames the Pralaya dialogue ethically: divine instruction and protection are presented as responding to Manu’s vow (vrata) and disciplined restraint (niyama), setting the moral tone for the Great Flood narrative.
It emphasizes that steadfast observance of vows and self-regulation are foundational duties; a ruler or householder who is firm in vrata-niyama becomes fit to receive right counsel and act in harmony with dharma.
No direct Vāstu or temple-building rule appears here; the ritual takeaway is the primacy of vrata and niyama—disciplined observance—as the qualifying basis for receiving sacred instruction.