Matsya Purana — Yuga Durations
यत्राधर्मश्चतुष्पादः स्याद्धर्मः पादविग्रहः कामिनस्तपसा हीना जायन्ते तत्र मानवाः //
yatrādharmaścatuṣpādaḥ syāddharmaḥ pādavigrahaḥ kāminastapasā hīnā jāyante tatra mānavāḥ //
Where unrighteousness stands firm on all four legs, and righteousness is left crippled—reduced to a single, broken footing—there human beings are born driven by desire, and devoid of austerity and self-discipline.
It does not describe Pralaya directly; it describes a moral decline where Adharma becomes dominant and Dharma becomes weakened—an ethical “end-time” symptom rather than a physical cosmic dissolution.
It warns that when society is ruled by desire and lacks tapas (restraint), Dharma collapses; a king must uphold discipline, justice, and moral education, and a householder must cultivate self-control to prevent Adharma from becoming socially “four-footed” and powerful.
No Vastu or iconographic rule is stated; the ritual takeaway is the centrality of tapas—regular discipline, vows, and restraint—as the inner support that keeps Dharma standing.