Matsya Purana — Genealogy from Budha to Purūravas and Yayāti; Raji’s war episode; the Paurava...
संस्थापयामास जरां तदा पुत्रे महात्मनि पौरवेणाथ वयसा राजा यौवनमास्थितः //
saṃsthāpayāmāsa jarāṃ tadā putre mahātmani pauraveṇātha vayasā rājā yauvanamāsthitaḥ //
Then the king placed his own old age upon his great-souled son Puru; and by that exchange of age, the king entered into youth again.
This verse does not discuss Pralaya; it belongs to a dynastic narrative where a king regains youth by transferring old age to his son, emphasizing lineage and moral causality rather than cosmic dissolution.
It highlights a kingship-and-householder tension: the king’s desire to continue youthful enjoyment leads to an extraordinary exchange, implicitly raising an ethical lesson about self-control, responsibility toward descendants, and proper succession (placing the burden of age/renunciation where it rightly belongs).
No Vastu, temple-building, or ritual procedure is stated in this verse; it is focused on royal genealogy and the moral consequences of personal desire and succession.