Matsya Purana — Account of the Manvantaras: Manus
वसिष्ठस्य सुताः सप्त ये प्रजापतयः स्मृताः द्वितीयमेतत्कथितं मन्वन्तरमतः परम् //
vasiṣṭhasya sutāḥ sapta ye prajāpatayaḥ smṛtāḥ dvitīyametatkathitaṃ manvantaramataḥ param //
The seven sons of Vasiṣṭha, remembered as Prajāpatis (progenitor-lords), have been spoken of; this is the second Manvantara. Thereafter, the next Manvantara is to be described.
It situates creation-history within cyclic time: Manvantaras succeed one another, and Prajāpatis function as progenitors within each cycle—implying recurring phases of manifestation after cosmic resets.
Indirectly, it grounds dharma in lineage and cosmic order: kings and householders are taught to see social duties (procreation, governance, ritual continuity) as aligned with Prajāpati-led creation and the rhythm of Manvantaras.
No explicit Vāstu or iconographic rule appears here; the ritual takeaway is the Purāṇic emphasis on preserving genealogical and calendrical knowledge used to time rites within a recognized cosmic chronology.