Matsya Purana — The Greatness of Prayaga: Manasa Tirtha
परिभ्रष्टस्तु राजेन्द्र सो ऽग्निहोत्री भवेन्नरः भुक्त्वा तु विपुलान्भोगांस् तत्तीर्थं भजते पुनः //
paribhraṣṭastu rājendra so 'gnihotrī bhavennaraḥ bhuktvā tu vipulānbhogāṃs tattīrthaṃ bhajate punaḥ //
O best of kings, even a man who has fallen from his proper religious observances becomes again an Agnihotrin—one who maintains the sacred fire. Having enjoyed abundant worldly pleasures, he once more resorts to that sacred ford (tīrtha).
This verse does not discuss Pralaya; it focuses on dharma-restoration through tīrtha-sevana, emphasizing moral and ritual renewal rather than cosmic dissolution.
It highlights that even one who has lapsed can return to Vedic household duties—especially maintaining Agnihotra—through renewed commitment and association with a tīrtha, a point relevant to kings who uphold dharma and householders who sustain sacred fires.
Ritually, it points to Agnihotra (the sacred fire observance) and tīrtha-sevana as a means of regaining eligibility and purity; no Vāstu or temple-construction rule is stated in this verse.