Adhyaya 89: शौचाचारलक्षणम् — सदाचार, भैक्ष्यचर्या, प्रायश्चित्त, द्रव्यशुद्धि, आशौच-निर्णय
अनुगम्य च वै स्नात्वा घृतं प्राश्य विशुध्यति आचार्यमरणे चैव त्रिरात्रं श्रोत्रिये मृते
anugamya ca vai snātvā ghṛtaṃ prāśya viśudhyati ācāryamaraṇe caiva trirātraṃ śrotriye mṛte
随行送葬之后再沐浴,以啜饮少许酥油(ghṛta)而得清净。若上师阿阇梨(ācārya)圆寂,或通晓吠陀的诵习者(śrotriya)去世,则不净(aśauca)之期为三夜。
Suta Goswami (narrating to the sages of Naimisharanya)
It sets the dharmic prerequisite of śauca (purity) after contact with death-related rites, indicating that proper purification is required before resuming Shiva-upasana and Linga-puja.
Implicitly, it presents Shiva as Pati (the Lord) approached through disciplined conduct: when the pashu (bound soul) observes śuddhi and restraint, the pasha of impurity and confusion is loosened, making the mind fit for devotion and knowledge.
Aśauca–śuddhi: bathing after the funeral-following rite and sipping ghee as a purificatory act, along with observing a three-night impurity period for the death of an ācārya or śrotriya—supporting the yogic discipline (niyama) that undergirds Pashupata-oriented Shiva worship.