Matsya Purana — Mandāra-Saptamī Vrata
नमस्कारेण तद्वच्च सूर्यायेत्यानले दले दक्षिणे तद्वदर्काय तथार्यम्णे च नैरृते //
namaskāreṇa tadvacca sūryāyetyānale dale dakṣiṇe tadvadarkāya tathāryamṇe ca nairṛte //
With a reverential salutation, in the south-east direction one should offer worship with the mantra “(obeisance) to Sūrya”; likewise, in the southern quarter one should worship Arka, and in the south-west (Nairṛta) one should worship Āryaman as well.
This verse is not about pralaya; it gives Vastu/ritual orientation rules—how specific solar deities (Ādityas) are to be worshipped in particular directions.
It supports the king/householder duty of maintaining correct ritual order (ācāra): performing worship with proper mantras and directional placements, which the Purāṇas treat as essential for prosperity, protection, and auspicious governance/household welfare.
It specifies directional assignment in a sacred layout (mandala): Sūrya in the south-east (Āgneya), Arka in the south, and Āryaman in the south-west (Nairṛta), guiding temple/altar planning and the sequence of invocations.