Matsya Purana — Sādhāraṇa Śrāddha: General Ancestral Rite
पूरयेत्पात्रयुग्मं तु स्थाप्य दर्भपवित्रकम् शं नो देवीत्य् अपः कुर्याद् यवो ऽसीति यवानपि //
pūrayetpātrayugmaṃ tu sthāpya darbhapavitrakam śaṃ no devīty apaḥ kuryād yavo 'sīti yavānapi //
He should fill a pair of vessels, setting in place the purifying darbha-grass. Reciting “Śaṃ no devīḥ…”, he should consecrate the water; and reciting “yavo ’si”, he should likewise sanctify the barley grains.
This verse is not about Pralaya; it focuses on ritual purity—sanctifying water and barley with Vedic mantras and darbha as a purifier.
It reflects the householder’s (and by extension a king’s) duty to perform rites correctly: preparing consecrated water and offerings with prescribed mantras and purity implements (darbha/kuśa).
Ritually, it specifies standard purification technology: darbha as a sanctifier and mantra-recitation to consecrate water and barley—key materials used in pūjā, homa, and other Vedic-Puranic ceremonies.