Matsya Purana — Solar–Lunar Motions
तिस्रस्तु वीथयो ह्येता उत्तरो मार्ग उच्यते पूर्वोत्तरा च फल्गुन्यौ मघा चैवार्षभी भवेत् //
tisrastu vīthayo hyetā uttaro mārga ucyate pūrvottarā ca phalgunyau maghā caivārṣabhī bhavet //
These are said to be the three vīthis (astral tracks/sections); the northern one is called the Uttara‑mārga (Northern Path). The north‑eastern track is associated with (Pūrva‑)Phalgunī, and Maghā is likewise to be understood as belonging to the Ārṣabhī (track/sector).
This verse is not about Pralaya; it belongs to a technical scheme that maps directions/paths (vīthis and mārga) to nakṣatras for auspicious orientation and planning.
It supports the king/householder’s duty to found towns, roads, and sacred buildings in an orderly and auspicious manner—using sanctioned directional and nakṣatra correspondences to reduce inauspiciousness and promote prosperity.
It encodes a Vāstu/Jyotiṣa rule: specific directional ‘tracks’ (vīthis) such as the Uttara Mārga and the north‑east track are linked with particular nakṣatras (Phalgunī, Maghā), guiding site-orientation, layout decisions, and timing/selection of works.