Matsya Purana — Dynastic Genealogies: Paurava–Anu Lines
उशिजस्य यवीयान्वै भ्रातृपत्नीमकामयत् बृहस्पतिर्महातेजा ममतामेत्य कामतः //
uśijasya yavīyānvai bhrātṛpatnīmakāmayat bṛhaspatirmahātejā mamatāmetya kāmataḥ //
Bṛhaspati, the greatly radiant one, came to Mamatā and, impelled by passion, desired the wife of Uśij’s younger brother.
Nothing directly—this verse is part of a lineage-episode narrative focusing on conduct and desire, not cosmic creation or pralaya.
It functions as a cautionary moral note: even exalted figures can fall under kāma (desire), underscoring the householder and ruler’s duty to restrain passion and protect familial/social order.
None is stated in this verse; it is narrative-ethical rather than Vāstu or ritual-instructional.