Matsya Purana — Solar–Lunar Motions
मानसोत्तरमेरोस्तु अन्तरं त्रिगुणं स्मृतम् सर्वतो दक्षिणस्यां तु काष्ठायां तन्निबोधत //
mānasottaramerostu antaraṃ triguṇaṃ smṛtam sarvato dakṣiṇasyāṃ tu kāṣṭhāyāṃ tannibodhata //
The interval between Mānasottara and Mount Meru is traditionally remembered as threefold in measure. And regarding the southern quarter in every respect—understand that direction clearly.
This verse is not about pralaya; it belongs to cosmographic description, giving a traditional proportional distance between Mānasottara and Meru and introducing clarification of the southern quarter.
Indirectly, it supports dharmic orientation: knowing directions (dik-jñāna) is used for correct ritual layout, travel, pilgrimage mapping, and auspicious planning—practical knowledge expected in royal administration and household rites.
The key technical term is kāṣṭhā (“direction/quarter”): directional certainty—especially the south (dakṣiṇā)—is foundational for Vāstu orientation and for placing ritual elements correctly according to prescribed quarters.