Adhyaya 89: शौचाचारलक्षणम् — सदाचार, भैक्ष्यचर्या, प्रायश्चित्त, द्रव्यशुद्धि, आशौच-निर्णय
सुप्त्वा भुक्त्वा च वै विप्राः क्षुत्त्वा पीत्वा च वै तथा ष्ठीवित्वाध्ययनादौ च शुचिरप्याचमेत्पुनः
suptvā bhuktvā ca vai viprāḥ kṣuttvā pītvā ca vai tathā ṣṭhīvitvādhyayanādau ca śucirapyācametpunaḥ
噢,婆罗门们:睡后、食后、喷嚏后、饮后,以及吐唾之后;并且在诵学吠陀等诸事之始——纵然自觉清净,也应再行阿遮摩那(净口礼)。
Suta Goswami (narrating dharma and ritual purity norms to the sages of Naimisharanya)
It sets a purity protocol: even minor bodily interruptions (sleep, food, sneeze, drink, spit) require ācamana so the worshipper approaches the Linga with renewed shauca, supporting mantra-śakti and ritual correctness.
By implication, Shiva as Pati is approached through disciplined purity; the devotee (pashu) reduces pasha-like impurities (mala and ritual doṣa) via regulated conduct, making the mind fit for Śiva-mantra and Śiva-arcana.
Ācamana as a recurring purificatory act before adhyayana and sacred actions—an outer shauca that steadies inner focus, aligning with Shaiva sadhana where bodily regulation supports mantra-japa and puja.