Matsya Purana — Cosmic Architecture of Sun–Moon and the ‘Houses of the Gods’
प्रभा सौरी तु पादेन अस्तं याति दिवाकरे अग्निमाविशते रात्रौ तस्मादग्निः प्रकाशते //
prabhā saurī tu pādena astaṃ yāti divākare agnimāviśate rātrau tasmādagniḥ prakāśate //
The sun’s radiance, as though with a single step, goes to its setting when the solar disc declines; at night it enters into fire—therefore fire shines forth (in the darkness).
It does not describe Pralaya directly; it offers a Purāṇic cosmological account of how solar tejas (radiance) is said to withdraw at sunset and manifest through Agni at night.
Indirectly, it supports the householder’s nightly reliance on sacred fire—maintaining Agni for light and rites—by grounding Agni’s luminosity in a cosmic principle tied to the Sun’s radiance.
Ritually, it reinforces the primacy of Agni in night-time worship and domestic rites (homa, dīpa/illumination), implying that fire/light is the proper medium for nocturnal observances.