Matsya Purana — The Madana-Dvādaśī Vow and the Birth of the Maruts
न मुक्तकेशा तिष्ठेत नाशुचिः स्यात्कदाचन न शयीतोत्तरशिरा न चापरशिराः क्वचित् //
na muktakeśā tiṣṭheta nāśuciḥ syātkadācana na śayītottaraśirā na cāparaśirāḥ kvacit //
One should not stand with the hair left loose, and one should never remain in a state of impurity. One should not lie down with the head toward the north, nor ever with the head toward the west.
This verse does not discuss pralaya; it focuses on dharmic conduct—maintaining cleanliness and observing direction-based restraints as part of disciplined living.
It prescribes everyday standards of decorum and ritual cleanliness (śauca) expected of householders and rulers alike, emphasizing self-regulation—proper grooming (not standing with loose hair), avoiding impurity, and observing auspicious directions while resting.
The directional rule (avoiding sleeping with the head to the north or west) aligns with traditional ritual-direction etiquette often echoed in Vastu-oriented practice, where orientation is treated as affecting auspiciousness and well-being.