Those who vow to worship Lord Śiva are so foolish that they imitate him by keeping long hair on their heads. When initiated into worship of Lord Śiva, they prefer to live on wine, flesh and other such things.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
नष्टशौचा मूढधियो जटाभस्मास्थिधारिणः । विशन्तु शिवदीक्षायां यत्र दैवं सुरासवम्
naṣṭaśaucā mūḍhadhiyo jaṭābhasmāsthidhāriṇaḥ | viśantu śivadīkṣāyāṃ yatra daivaṃ surāsavam
SB 4.2.29