Matsya Purana — Kārtavīrya Arjuna’s Solar Boon and the Genealogy from Kroṣṭu to the Yādava Lines
एतस्मिन्नेव काले तु आपवो जलमास्थितः दश वर्षसहस्राणि तत्रास्ते स महानृषिः //
etasminneva kāle tu āpavo jalamāsthitaḥ daśa varṣasahasrāṇi tatrāste sa mahānṛṣiḥ //
At that very time, the great sage Āpava, having taken refuge in the waters, remained there for ten thousand years.
It highlights the prolonged duration and severity of the deluge-era conditions, indicating that exalted sages could endure and remain sustained in the waters for vast spans (ten thousand years), a hallmark of pralaya-time descriptions.
Indirectly, it reinforces the Purāṇic ethic of preparedness and steadfastness during cosmic upheaval—an ideal mirrored in royal and household duties: preserving dharma, safeguarding dependents, and maintaining discipline through long trials.
No direct Vāstu or temple-rule detail appears in this verse; its ritual takeaway is the ascetic ideal of sustained tapas and yogic endurance, often treated as the inner ‘support’ that complements outer ritual and sacred construction.