Adhyaya 89: शौचाचारलक्षणम् — सदाचार, भैक्ष्यचर्या, प्रायश्चित्त, द्रव्यशुद्धि, आशौच-निर्णय
दिवास्वप्नं विशेषेण तथा वै दन्तधावनम् मैथुनं मानसं वापि वाचिकं देवतार्चनम्
divāsvapnaṃ viśeṣeṇa tathā vai dantadhāvanam maithunaṃ mānasaṃ vāpi vācikaṃ devatārcanam
In particular, daytime sleep, and likewise the brushing/cleaning of the teeth; and indulgence in sexual union, whether in mind or in speech—these are to be avoided in the worship of the Deity. Such restraints preserve purity and one-pointedness for Śiva-arcana, leading the paśu away from pāśa toward the grace of Pati (Śiva).
Suta Goswami
It sets behavioral restraints—especially avoiding daytime sleep and sexual indulgence in thought or speech—so the worshipper maintains śauca (purity) and ekāgratā (one-pointed focus) for Śiva-liṅga arcana.
By implication, Śiva is approached as Pati, the liberating Lord, through inner and outer purity; the verse stresses that bondage (pāśa) persists when the mind and speech remain entangled in sense-impulses.
A discipline of niyama for pūjā—restraint of body, speech, and mind (especially regarding maithuna)—aligned with Pāśupata-style control of vṛttis to keep the arcana inwardly pure.