Matsya Purana — Glory of Tīrtha-Śrāddha: Best Times
श्राद्धमेतेषु सर्वेषु कोटिकोटिगुणं भवेत् स्मरणादपि पापानि नश्यन्ति शतधा द्विजाः //
śrāddhameteṣu sarveṣu koṭikoṭiguṇaṃ bhavet smaraṇādapi pāpāni naśyanti śatadhā dvijāḥ //
O twice-born ones (dvijas), when the Śrāddha rite is performed in all these places, its merit is multiplied by crores upon crores; even by mere remembrance, sins are destroyed a hundredfold.
This verse is not about pralaya; it emphasizes dharma through Śrāddha, teaching that ritual merit and even remembrance can powerfully remove sin.
It supports the gṛhastha duty of honoring ancestors and maintaining ritual order; performing Śrāddha as prescribed is presented as a major source of merit and purification.
The significance is ritual (not architectural): Śrāddha performed in the recommended contexts yields immense multiplied merit, and even mindful recollection is said to destroy sins.