Shiva Purana
विश्वेश्वरेऽपि ये भक्ता नो भक्ताः कालभैरवे ॥ ते लभन्ते महादुःखं काश्यां चैव विशेषतः ॥ ६८ ॥
The devotees of lord Śiva, who do not show devotion for Kālabhairava, attain great sorrow and especially so at Kāśī.
english translation
vizvezvare'pi ye bhaktA no bhaktAH kAlabhairave ॥ te labhante mahAduHkhaM kAzyAM caiva vizeSataH ॥ 68 ॥
hk transliteration by Sanscript