Linga Purana — Purva Bhaga, Shloka 13
लिङ्गार्चनपूर्वकं स्नानाचमनविधिः
Snana–Achamana as Preparation for Linga-Archana
मृच्छकृत्तिलपुष्पं च स्नानार्थं भसितं तथा आदाय तीरे निःक्षिप्य स्नानतीर्थे कुशानि च
mṛcchakṛttilapuṣpaṃ ca snānārthaṃ bhasitaṃ tathā ādāya tīre niḥkṣipya snānatīrthe kuśāni ca
取土与泥、芝麻与花，并取用于沐浴的圣灰（bhasma），携至岸边置放；在沐浴渡口（tīrtha）亦当安置库沙草（kuśa）。如是，奉献者先备净化之具，然后亲近湿婆——帕提（Pati），解开束缚灵魂（paśu）的绳索（pāśa）之主。
Suta Goswami (narrating to the sages of Naimisharanya)
FAQs
It prescribes the practical preliminaries—gathering and setting aside clay/earth, sesame, flowers, vibhuti, and kuśa—so the sādhaka enters Shiva-puja through orderly purification (śauca) and readiness at the tīrtha.
By emphasizing purification before worship, the verse implies Shiva as Pati—the supreme Lord approached through inner and outer cleansing—who grants release to the paśu from pasha, even when the approach begins with simple ritual acts.
Tīrtha-snāna with vibhūti (sacred ash) and the use of kuśa grass—foundational Shaiva purificatory observances that support Pashupata-oriented discipline and focused worship.