Jyotiṣa-saṅgraha: Varga-vibhāga, Bala-nirṇaya, Garbha-phala, Āyuḥ-gaṇanā
मंदार्चने वा तमसि शयनं नीचगेभुवि । शीर्षे पृष्टोदये जन्म तद्वदेव विनिर्दिशेत् ॥ ८५ ॥
maṃdārcane vā tamasi śayanaṃ nīcagebhuvi | śīrṣe pṛṣṭodaye janma tadvadeva vinirdiśet || 85 ||
If one sleeps in darkness, or lies down on low ground, or is born when the ascendant is in the head region and the back is rising, one should understand the indicated result to be the same as stated earlier.
Sanatkumara (teaching Narada)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: bhayanaka
It treats certain conditions—darkness, improper sleeping places, and specific birth-time indications—as inauspicious nimittas, teaching vigilance in conduct and timing as part of Dharma-oriented living.
Indirectly: by discouraging tamasic habits and inauspicious settings, it supports a sattvic lifestyle that traditionally aids steadiness of mind, which is favorable for Vishnu-bhakti and disciplined practice.
Jyotiṣa/Nimitta-style reasoning: interpreting birth-time and situational signs as carrying predictable outcomes, and classifying certain timings/conditions as equivalent in result to previously described inauspicious indicators.