Matsya Purana — Bhīma-Dvādaśī
यस्य तीक्ष्णो वृको नाम जठरे हव्यवाहनः मया दत्तः स धर्मात्मा तेन चासौ वृकोदरः //
yasya tīkṣṇo vṛko nāma jaṭhare havyavāhanaḥ mayā dattaḥ sa dharmātmā tena cāsau vṛkodaraḥ //
He of righteous soul, in whose belly I placed the fierce fire named Vṛka—the carrier of oblations (havyavāhana)—is therefore called Vṛkodara, “Vṛka-bellied (wolf-bellied)”.
Nothing directly—this verse is not about Pralaya; it explains a heroic epithet through an Agni-related etymology.
Indirectly, it praises dharma by calling the person “dharmātmā,” implying that true strength (symbolized by inner fire) should be grounded in righteousness—an ethical ideal for rulers and householders alike.
Ritually, “Havyavāhana” points to Agni as the carrier of offerings in yajña; the verse uses sacrificial-fire terminology to frame a name-origin, not a Vāstu or temple-building rule.