Matsya Purana — The Greatness of Prayaga: Manasa Tirtha
स्वर्गे च शक्रलोके ऽस्मिन् नृषिगन्धर्वसेविते परिभ्रष्टस्तु राजेन्द्र समृद्धे जायते कुले //
svarge ca śakraloke 'smin nṛṣigandharvasevite paribhraṣṭastu rājendra samṛddhe jāyate kule //
And in this heaven—the realm of Śakra (Indra), frequented by seers and Gandharvas—when one falls from there, O king of kings, one is born into a prosperous family.
This verse is not about Pralaya; it teaches karma-phala: after enjoying Indra’s heaven, a being who falls from that state is reborn on earth—specifically into a prosperous lineage.
By addressing “O best of kings,” it frames prosperity and noble birth as results of accumulated merit (puṇya), encouraging rulers and householders to uphold dharma, charity, and righteous conduct to secure auspicious rebirth outcomes.
No Vāstu or temple-building rule is stated here; the verse’s ritual takeaway is the broader Purāṇic idea that meritorious rites and dharmic acts can lead to Svarga and, after its exhaustion, rebirth in a wealthy family.