Matsya Purana — Rite and Layout for Consecrating Ponds
शाक्रं रौद्रं च सौम्यं च कूष्माण्डं जातवेदसम् सौरसूक्तं जपेन्मन्त्रं दक्षिणेन यजुर्विदः //
śākraṃ raudraṃ ca saumyaṃ ca kūṣmāṇḍaṃ jātavedasam saurasūktaṃ japenmantraṃ dakṣiṇena yajurvidaḥ //
One who knows the Yajurveda in the southern recension should recite as japa the Śākra, Raudra, and Saumya mantras, as well as the Kūṣmāṇḍa and Jātavedas formulas, and the Saura-sūkta.
This verse is not about pralaya; it is a ritual prescription listing specific deity-linked mantras and a Saura Sūkta to be recited as japa by a Yajurvedic adept.
It frames a practical dharmic duty: disciplined mantra-recitation (japa) according to one’s Vedic tradition, invoking Indra, Rudra, Soma, Agni (Jātavedas), and Sūrya for protection, order, and wellbeing—relevant to household rites and royal welfare-rituals alike.
The significance is ritual (not architectural): it specifies an authorized set of mantras/sūktas—especially the Saura Sūkta—for recitation within the southern Yajurvedic tradition, indicating lineage-specific liturgical practice.