Matsya Purana — Bhīma-Dvādaśī
ब्रूयात् सायन्तनीं कृत्वा संध्यामस्तमिते रवौ नमो नारायणायेति त्वामहं शरणं गतः //
brūyāt sāyantanīṃ kṛtvā saṃdhyāmastamite ravau namo nārāyaṇāyeti tvāmahaṃ śaraṇaṃ gataḥ //
Having performed the evening Sandhyā at sunset, one should recite: “Obeisance to Nārāyaṇa—O Lord, I have taken refuge in You.”
It does not describe Pralaya directly; instead it teaches a daily discipline—sunset Sandhyā—grounded in surrender to Nārāyaṇa, a stance that Purāṇas often present as spiritual protection in all cosmic conditions.
It frames Sandhyā at sunset as a required daily observance and adds a clear bhakti formula—“namo nārāyaṇāya… śaraṇaṃ gataḥ”—showing that righteous life (for king or householder) includes regular worship and conscious refuge in Viṣṇu/Nārāyaṇa.
The significance is ritual rather than architectural: it specifies the proper timing (sunset) and the devotional utterance to be recited after performing the evening Sandhyā.