Matsya Purana — Genealogy and Classification of Sacred Fires
वासवो ऽग्निः कृशानुर्यो द्वितीयोत्तरवेदिकः सम्राडग्निसुतो ह्यष्टाव् उपतिष्ठन्ति तान्द्विजाः //
vāsavo 'gniḥ kṛśānuryo dvitīyottaravedikaḥ samrāḍagnisuto hyaṣṭāv upatiṣṭhanti tāndvijāḥ //
That fire is called Vāsava and also Kṛśānu; it is the second, stationed upon the northern altar-platform. Samrāṭ, the son of Agni—these eight (forms/attendants) are duly attended upon by the dvija, the twice-born (Brahmins).
This verse is not about Pralaya; it focuses on ritual taxonomy—naming and positioning forms of Agni and stating that dvijas must attend them according to prescribed worship.
It underscores dharma through yajña: householders (and rulers who sponsor sacrifices) must maintain correct fire-ritual practice, while dvijas perform the formal attending/worship of the designated fires on properly oriented altars.
It specifies altar-orientation and placement—“uttara-vedi” (northern altar/platform) for the ‘second’ fire—linking ritual correctness to spatial layout, a key intersection of yajna-vidhi and Vastu-style directional discipline.