Adhyaya 89: शौचाचारलक्षणम् — सदाचार, भैक्ष्यचर्या, प्रायश्चित्त, द्रव्यशुद्धि, आशौच-निर्णय
बेहविओउर् ओफ़् अ योगिन् योगिनां चैव सर्वेषां श्रेष्ठं चान्द्रायणं भवेत् एकं द्वे त्रीणि चत्वारि शक्तितो वा समाचरेत्
behaviour of a yogin yogināṃ caiva sarveṣāṃ śreṣṭhaṃ cāndrāyaṇaṃ bhavet ekaṃ dve trīṇi catvāri śaktito vā samācaret
For a yogin—and indeed among all yogins—the Cāndrāyaṇa observance is declared the foremost. According to one’s capacity, one should undertake it once, twice, thrice, or even four times, as an inner purification that supports steadfast devotion to Pati (Śiva) and loosens the pāśa that binds the paśu (the individual soul).
Suta Goswami (narrating the Linga Purana’s teaching to the sages at Naimisharanya)
It elevates the Cāndrāyaṇa vrata as a premier purifier for practitioners, making the worshipper fit for steady Śiva-bhakti and disciplined Linga-upāsanā by reducing impurity and strengthening restraint.
By implying Śiva as Pati—the supreme Lord—whose realization is supported by purification; the soul (pashu) approaches Śiva-tattva as bonds (pāśa) are weakened through such observances.
The Cāndrāyaṇa observance (a lunar-cycle penance/discipline) is highlighted, to be undertaken according to one’s strength, even repeatedly (up to four times) for deeper purification.