Matsya Purana — The Kauśika Descendants: Śrāddha
तन्मध्ये ये तु निष्कामास् ते बभूवुर् द्विजोत्तमाः विभ्राजपुत्रस्त्वेको ऽभूद् ब्रह्मदत्त इति स्मृतः //
tanmadhye ye tu niṣkāmās te babhūvur dvijottamāḥ vibhrājaputrastveko 'bhūd brahmadatta iti smṛtaḥ //
Among them, those who were free from selfish desire became the foremost of the dvijas (the twice-born). And among the sons of Vibhrāja, one was renowned and remembered by the name Brahmadatta.
This verse is not describing Pralaya; it is part of a genealogical-ethical note where desirelessness (niṣkāma) is presented as a mark of exemplary twice-born persons.
By praising niṣkāma conduct, the verse supports the broader Purāṇic ethic that rulers and householders should act without selfish attachment—protecting, giving, and performing duties for dharma rather than personal gain.
No direct Vāstu or temple-ritual rule appears here; the verse functions mainly as a genealogical identification (Brahmadatta, son in Vibhrāja’s line) with an ethical qualifier (niṣkāma).