Matsya Purana — Ekoddiṣṭa Śrāddha
आमश्राद्धं यदा कुर्याद् विधिज्ञः श्राद्धदस्तदा तेनाग्नौकरणं कुर्यात् पिण्डांस्तेनैव निर्वपेत् //
āmaśrāddhaṃ yadā kuryād vidhijñaḥ śrāddhadastadā tenāgnaukaraṇaṃ kuryāt piṇḍāṃstenaiva nirvapet //
Whenever a ritual expert performs an āma-śrāddha (an unelaborated śrāddha), then, being duly engaged in the śrāddha, he should also perform the agnaukaraṇa rite by that same procedure, and by that very method he should duly offer the piṇḍas (rice-balls) as well.
This verse does not address pralaya; it focuses on dharma in the form of śrāddha procedure—how a simplified āma-śrāddha still includes agnaukaraṇa and proper piṇḍa-offering.
It directly supports gṛhastha-dharma (householder duty): even when performing a simpler śrāddha, one should follow the required ancillary rite (agnaukaraṇa) and correctly offer the piṇḍas, maintaining continuity of ancestral obligations (pitṛ-yajña).
The significance is ritual: it standardizes śrāddha performance by stating that agnaukaraṇa and piṇḍa offerings should be carried out in the same consistent manner during āma-śrāddha.