उमामहेश्वरव्रतं—पञ्चाक्षरमन्त्रस्य माहात्म्यं, न्यासः, जपविधिः, सदाचारः, विनियोगः
मिथ्या न कारयेद्देवि क्रियया च गुरोः सदा दुर्गुणे ख्यापिते तस्य नैर्गुण्यशतभाग्भवेत्
mithyā na kārayeddevi kriyayā ca guroḥ sadā durguṇe khyāpite tasya nairguṇyaśatabhāgbhavet
おおデーヴィーよ、師(グル)について、作為の行いによって虚偽を決して作り出してはならない。師の「欠点」を言い広める者は、その罪過を百倍に受け、穢れとパーシャ(pāśa)の束縛をいよいよ強める。
Suta Goswami (narrating the Purana; verse framed as a Devi-address within the teaching)
It establishes inner purity as a prerequisite for Shiva-puja: slandering or inventing faults about one’s Guru creates heavy demerit, obstructing mantra-siddhi and the fruit of Linga worship.
By implication, Shiva-tattva is accessed through disciplined truthfulness and reverence toward the Guru, who functions as the channel of Śiva’s grace (anugraha) that cuts pasha for the pashu.
The discipline of guru-sevā and vāg-niyama (restraint of speech) is emphasized as part of Shaiva sādhanā—supporting Pashupata practice by preventing karmic accrual through nindā (censure).