Matsya Purana — Characteristics of Dvāpara and Kali Yugas
समास्त्रिंशत्तु सम्पूर्णाः पर्यटन्वै वसुंधराम् अश्वकर्मा स वै सेनां हस्त्यश्वरथसंकुलाम् //
samāstriṃśattu sampūrṇāḥ paryaṭanvai vasuṃdharām aśvakarmā sa vai senāṃ hastyaśvarathasaṃkulām //
For a full thirty years indeed, Aśvakarmā roamed over the earth, moving with an army crowded with elephants, horses, and chariots.
This verse does not address pralaya; it is a dynastic-martial description of a king/leader roaming the earth with a fourfold-style force emphasizing elephants, horses, and chariots.
It reflects the kingly sphere (rājadharma in practice): maintaining and leading an organized army and undertaking prolonged tours/campaigns across the realm—activities tied to protection, assertion of sovereignty, and oversight of territories.
No direct Vastu or ritual procedure is stated; the key technical detail is military composition—an army ‘thronged with elephants, horses, and chariots,’ a standard Purāṇic marker of royal power.