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
イーシャーナ(北東)の方位では、その運行は夜の第一の更に属すると説かれる。まことにこの動きは遍く理解されている。かくしてプシュカラのただ中で、威徳ある水が滑るように流れ進むとき、これこそ定められた法の相である。
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.