Matsya Purana — Account of the Manvantaras: Manus
हिरण्यरोमा सप्ताश्वः सप्तैते ऋषयः स्मृताः देवाश्चाभूतरजसस् तथा प्रकृतयः शुभाः //
hiraṇyaromā saptāśvaḥ saptaite ṛṣayaḥ smṛtāḥ devāścābhūtarajasas tathā prakṛtayaḥ śubhāḥ //
Hiraṇyaromā and Saptāśva are remembered as among the seven Ṛṣis; and likewise the gods of the Abhūtarajas group, as well as the auspicious Prakṛtis (primordial constituents), are also spoken of.
It functions as a creation-era catalogue: it names sage-groups and divine classes (like Abhūtarajas) and mentions Prakṛtis, implying an ordered cosmos constituted by primordial principles rather than describing the flood or dissolution directly.
Indirectly, it grounds dharma in cosmic order: by recognizing established classes of sages and gods, the king/householder is reminded that social and ritual duties align with a larger, inherited (smṛta) structure of the universe.
No direct Vāstu rule appears, but the mention of Prakṛtis supports the Purāṇic idea that ritual and temple practice should mirror cosmic constituents and hierarchies—an underlying principle later used in iconography and sacred architecture.