Adhyaya 89: शौचाचारलक्षणम् — सदाचार, भैक्ष्यचर्या, प्रायश्चित्त, द्रव्यशुद्धि, आशौच-निर्णय
तस्मात्सर्वप्रयत्नेन न संभाष्या रजस्वला प्रथमे ऽहनि चाण्डाली यथा वर्ज्या तथाङ्गना
tasmātsarvaprayatnena na saṃbhāṣyā rajasvalā prathame 'hani cāṇḍālī yathā varjyā tathāṅganā
فلذلك، وبكل اجتهاد، لا ينبغي مخاطبةُ المرأة الحائض في اليوم الأول؛ ففي ذلك اليوم تُجتَنَب كما يُجتَنَبُتْ امرأةٌ من طبقةِ «تشاندالي»، وكذلك تُجعَل تلك المرأةُ في عُزلةٍ وانفصال.
Suta Goswami (narrating Linga Purana teachings to the sages of Naimisharanya)
It frames shaucha (ritual discipline) as a preparatory boundary for approaching Shiva-linga worship, emphasizing temporary separation on the first day as part of maintaining ritual readiness.
Indirectly, it presents Shiva as Pati—the supremely pure Lord—whose worship is approached through regulated conduct; the pashu (individual) reduces pasha (impurities/constraints) by observances that cultivate fitness for puja.
A shaucha-based restriction: on the first day of menstruation, one avoids close interaction as part of maintaining ritual purity norms connected to Shiva-puja discipline.