Matsya Purana — The Attendant Hosts of the Sun and Moon: Monthly Gaṇas
मासेन तच्चामृतमस्य मृष्टं सुवृष्टये रश्मिषु रक्षितं तु सर्वे ऽमृतं तत्पितरः पिबन्ति देवाश्च सौम्याश्च तथैव काव्याः //
māsena taccāmṛtamasya mṛṣṭaṃ suvṛṣṭaye raśmiṣu rakṣitaṃ tu sarve 'mṛtaṃ tatpitaraḥ pibanti devāśca saumyāśca tathaiva kāvyāḥ //
Month by month, that nectar (amṛta) of his is refined and, for the sake of abundant rainfall, is preserved within his rays. That very ambrosia is drunk by all the Pitṛs, and also by the Devas—along with the Saumyas and likewise the Kāvyas.
It does not describe Pralaya directly; it explains ongoing cosmic maintenance—Soma’s refined “amṛta” preserved in moon-rays supports rainfall and sustains Devas and Pitṛs, showing how the universe is ritually and cosmically nourished.
By linking Pitṛs’ sustenance to a cosmic nectar-cycle, it reinforces the householder’s duty of śrāddha and tarpaṇa (ancestral offerings). A king, as guardian of dharma, should uphold such rites publicly so prosperity (symbolized by timely rains) and social order remain steady.
The ritual takeaway is central: Soma’s “amṛta” feeding Pitṛs and Devas underlines the importance of lunar-timed rites (śrāddha, tarpaṇa) and rain-linked yajña logic; no direct Vāstu/temple-construction rule is stated in this verse.