Matsya Purana — Inquiry into Taraka’s Slaying and the Prelude to Guha
वराङ्गीति च नामास्याः कृत्वा यातः पितामहः वज्राङ्गो ऽपि तया सार्धं जगाम तपसे वनम् //
varāṅgīti ca nāmāsyāḥ kṛtvā yātaḥ pitāmahaḥ vajrāṅgo 'pi tayā sārdhaṃ jagāma tapase vanam //
Having given her the name “Varāṅgī,” the grandsire departed; and Vajrāṅga too, together with her, went to the forest to undertake austerities (tapas).
This verse does not describe Pralaya; it focuses on a lineage episode—naming (Varāṅgī) and the choice of forest austerities (tapas) as a spiritually elevating act.
It reflects the Purāṇic model where even royals or eminent figures may renounce comfort for tapas, showing that dharma includes self-discipline, restraint, and the pursuit of spiritual merit alongside worldly responsibilities.
No Vāstu/temple rule is stated here; the ritual note is the act of naming (nāmakaraṇa-style identification) and the religious practice of undertaking tapas in the forest.