Matsya Purana — Yuga Durations
यत्र धर्मश्चतुष्पादस् त्व् अधर्मः पादविग्रहः स्वधर्मनिरताः सन्तो जायन्ते यत्र मानवाः //
yatra dharmaścatuṣpādas tv adharmaḥ pādavigrahaḥ svadharmaniratāḥ santo jāyante yatra mānavāḥ //
Where Dharma stands firm on all four feet, while Adharma is crippled—deprived of its footing—there are born virtuous people devoted to their own rightful duties.
It does not describe Pralaya directly; it defines a stable moral order where Dharma is complete and Adharma is weakened, implying social continuity rather than cosmic dissolution.
It presents the king’s ideal outcome of governance: establishing conditions where Dharma is ‘four-footed’ (fully supported) so that people naturally adhere to svadharma—householders, in turn, sustain society by faithfully performing their rightful duties.
No direct Vastu or ritual rule is stated; the takeaway is contextual—temple-building and rites are fruitful only in a realm where Dharma is firmly established and Adharma is restrained.