Matsya Purana — Soma
निर्मुच्यमानयोर्मध्ये तयोर्मण्डलयोस्तु वै स तदान्वाहुतेः कालो दर्शस्य च वषट्क्रियाः एतदृतुमुखं ज्ञेयम् अमावास्यां तु पार्वणम् //
nirmucyamānayormadhye tayormaṇḍalayostu vai sa tadānvāhuteḥ kālo darśasya ca vaṣaṭkriyāḥ etadṛtumukhaṃ jñeyam amāvāsyāṃ tu pārvaṇam //
In the interval when the two luminary discs are, as it were, disengaging from one another, that very time is declared the proper moment for the anvāhuta offering and for the vaṣaṭ-invocations of the Darśa rite. This is to be known as the “opening of the season” (ṛtu-mukha); and the Parva observance is to be performed on Amāvāsyā, the new-moon day.
This verse is not about Pralaya; it focuses on ritual calendrics—identifying the correct time for Darśa (new-moon) offerings and the Parva observance on Amāvāsyā.
It supports dharma through correct performance of household and state-supported rites—timing the Darśa/Amāvāsyā observances properly, which a gṛhastha (and a king as patron of ritual order) is expected to uphold.
Ritual significance: it specifies the auspicious/authorized ritual window for the anvāhuta oblation and vaṣaṭ invocations in the Darśa rite, and states that Parva rites are to be done on Amāvāsyā, marking ṛtu-mukha (seasonal commencement).