Matsya Purana — Manvantaras
आत्मवत्सर्वभूतेषु यो हिताय शुभाय च वर्तते सततं हृष्टः क्रिया श्रेष्ठा दया स्मृता //
ātmavatsarvabhūteṣu yo hitāya śubhāya ca vartate satataṃ hṛṣṭaḥ kriyā śreṣṭhā dayā smṛtā //
One who regards all beings as oneself and continually acts for their welfare and good, ever remaining glad—such conduct is remembered as the highest deed: compassion (dayā).
This verse does not discuss Pralaya directly; it teaches an ethical principle—universal empathy and welfare-oriented conduct—as a core dharmic virtue.
It frames righteous duty as acting for the welfare and auspicious good of all beings with an “ātma-vat” outlook; for a king this supports benevolent governance and protection, and for a householder it supports non-harm, charity, and daily kindness as the highest practical virtue.
No Vāstu or ritual procedure is stated here; the takeaway is that compassion itself is treated as the श्रेष्ठ (highest) ‘kriyā’—a guiding principle that can inform all ritual and social actions.