Jyotiṣa-śāstra Saṅgraha: Threefold Division, Gaṇita Methods, Muhūrta, and Planetary Reckoning
रेखा प्राच्यपरा साध्या विषुवद्भाग्रया तथा । इष्टच्छायाविषुवतोर्मध्येह्यग्राभिधीयते ॥ १३४ ॥
rekhā prācyaparā sādhyā viṣuvadbhāgrayā tathā | iṣṭacchāyāviṣuvatormadhyehyagrābhidhīyate || 134 ||
Garis yang menghadap ke timur hendaknya digambar, demikian pula garis ekuinoks (timur–barat). Titik yang disebut ‘agrā’ berada tepat di tengah antara tanda bayangan yang diinginkan dan tanda ekuinoks itu.
Sanatkumara (teaching Narada in a technical-vedanga style passage)
Vrata: none
Primary Rasa: shanta
Secondary Rasa: bhakti
It shows that dharma and moksha-oriented life in the Purana is supported by precise knowledge (vidyā): correct orientation and time-reckoning (through shadow and equinoctial markers) safeguard the accuracy of rites and disciplined living.
While not directly a bhakti-verse, it supports bhakti-practice indirectly: accurate determination of direction and time helps perform Vishnu-oriented worship, vrata timings, and daily observances with steadiness and correctness.
Vedāṅga Jyotiṣa and chāyā-gaṇita (shadow-based measurement): drawing an east-oriented line, using the equinoctial (viṣuvat) reference, and defining a midpoint marker (agrā) for further calculation or alignment.