Matsya Purana — Yadu Lineage
यदि कृत्स्नो मया धर्मो ज्ञायते चरितो ऽपि वा तेन सत्येन जीवस्व यदि सत्यं वदाम्यहम् //
yadi kṛtsno mayā dharmo jñāyate carito 'pi vā tena satyena jīvasva yadi satyaṃ vadāmyaham //
If I have truly understood the whole of dharma, and have also practiced it, then by that truth may you live—if I am speaking the truth.
It reflects the pralaya setting indirectly: Manu seeks protection and survival through a satya-assertion, a common Purāṇic motif where truth is invoked as a saving force amid cosmic dissolution.
It frames dharma not only as knowledge but as lived conduct; the speaker claims both understanding and practice of duty, implying that a ruler/householder’s ethical integrity (truthfulness and dharma) is the foundation of protection and legitimacy.
No Vāstu or temple-architecture rule is stated here; the ritual significance is the satyavacana (truth-declaration) used as a protective vow/prayer, highlighting truth as an efficacious spiritual act.