भुवनकोशविन्यासनिर्णयः (ज्योतिर्गति-वृष्टिचक्र-वर्णनम्)
ईशान्यां पूर्वरात्रस्तु गतिरेषा च सर्वतः एवं पुष्करमध्ये तु यदा सर्पति वारिपः
īśānyāṃ pūrvarātrastu gatireṣā ca sarvataḥ evaṃ puṣkaramadhye tu yadā sarpati vāripaḥ
Di arah Īśāna (timur laut), haluan itu dikatakan milik jaga pertama malam; sesungguhnya gerak ini difahami di mana-mana. Demikianlah, di tengah Puṣkara, tatkala air yang mulia meluncur dan mengalir ke hadapan, itulah pola yang telah ditetapkan.
Suta Goswami
It links Īśāna—Shiva’s north‑eastern quarter—with proper ritual timing (the first night-watch), implying that Linga-pūjā gains potency when aligned with dik (direction) and kāla (time) as ordained in the Purāṇic ritual order.
By invoking Īśāna, it points to Shiva as Pati—the supreme regulator of cosmic order—whose presence is apprehended through sacred orientation and the lawful movement of tīrtha-waters, guiding the pashu (soul) toward purity and release from pāśa (bondage).
Directional and time-based observance: selecting the Īśāna quarter and the first watch of night for tīrtha-related rites (snāna, japa, and Linga-pūjā), reflecting the Shaiva discipline of harmonizing practice with dik–kāla.