Matsya Purana — Yadu Lineage
*सूत उवाच त्यक्त्वा दिव्यां तनुं विष्णुर् मानुषेष्विह जायते युगे त्व् अथ परावृत्ते काले प्रशिथिले प्रभुः //
*sūta uvāca tyaktvā divyāṃ tanuṃ viṣṇur mānuṣeṣviha jāyate yuge tv atha parāvṛtte kāle praśithile prabhuḥ //
Sūta said: Casting aside His divine form, Lord Viṣṇu is born here among human beings; and when the yuga has turned and time has grown slackened, the Sovereign Lord manifests again.
It does not describe pralaya directly; it explains the avatāra principle—when time turns at a yuga transition and order weakens, Viṣṇu manifests among humans to restore balance.
By implying dharma can become “slackened” with time, it frames kings and householders as responsible for sustaining dharma; when they fail collectively, divine intervention becomes necessary—so righteous governance and disciplined conduct are the preventative ideal.
No direct Vāstu or ritual procedure is stated; the verse is theological, establishing the timing and purpose of divine manifestation rather than temple-building or rites.