उमामहेश्वरव्रतं—पञ्चाक्षरमन्त्रस्य माहात्म्यं, न्यासः, जपविधिः, सदाचारः, विनियोगः
पेर्फ़ोर्मिन्ग् आसन अनासनः शयानो वा रथ्यायां शूद्रसन्निधौ रक्तभूम्यां च खट्वायां न जपेज्जापकस् तथा
performing āsana anāsanaḥ śayāno vā rathyāyāṃ śūdrasannidhau raktabhūmyāṃ ca khaṭvāyāṃ na japejjāpakas tathā
同样,修持咒念者不应在无稳固坐处而来回变动时诵念,也不应卧诵;不应在公共街道上诵念,不应在首陀罗近旁诵念,不应在染血之地诵念,也不应在床榻上诵念。此等境况障碍清净与内在一心,使人难以凭真言亲近主宰帕提(湿婆)。
Suta Goswami
It sets boundary-conditions for japa so the worshipper maintains śauca (ritual purity) and ekāgratā (one-pointedness), allowing mantra to become an effective means of approaching the Linga as Pati.
Shiva is implied as Pati—approached through mantra only when the pashu (individual soul) restrains distracting and impure conditions that strengthen pāśa (bondage) like restlessness and tamasic surroundings.
Mantra-japa discipline: recite in a stable, clean, and inwardly conducive setting—avoiding lying down, public roads, impure places, and other proximity rules—so the mantra remains sāttvika and focused.