Matsya Purana — Nārāyaṇa as Haṃsa in the Cosmic Ocean: Vedic Yajña-Puruṣa and Mārkaṇḍeya’s Vi...
उदरात्प्रतिहर्तारं पोतारं चैव पार्थिव अच्छावाकमथोरुभ्यां नेष्टारं चैव पार्थिव //
udarātpratihartāraṃ potāraṃ caiva pārthiva acchāvākamathorubhyāṃ neṣṭāraṃ caiva pārthiva //
From among those connected with the Udara (a designated group/line for this office), O king, one should appoint the Pratihartṛ and the Potṛ; likewise, from the two Urubhyas one should appoint the Acchāvāka and also the Neṣṭṛ, O king.
This verse is not about Pralaya; it outlines technical appointments of specific Śrauta-yajña officiants (Pratihartṛ, Potṛ, Acchāvāka, Neṣṭṛ) and therefore belongs to ritual-administrative instruction rather than cosmology.
It frames priestly selection as a kingly duty: ensuring sacrifices are conducted by correctly designated specialists from the proper groups/lines, reflecting Rajadharma—maintaining order, orthopraxy, and legitimacy of public rites.
Ritual significance: it specifies which categories/groups should supply key Soma-rite functionaries (Potṛ, Acchāvāka, Neṣṭṛ, etc.), emphasizing correct staffing as essential for a valid Vedic sacrifice.