Shiva Purana
सर्वे रुद्रं भजन्त्येव रुद्रः कञ्चिद्भजेन्न हि ॥ स्वात्मना भक्तवात्सल्याद्भजत्येव कदाचन ॥ १५ ॥
All worship Rudra but Rudra does not worship any one. Yet due to his favourable attitude to his devotees sometimes he worships himself.
english translation
sarve rudraM bhajantyeva rudraH kaJcidbhajenna hi ॥ svAtmanA bhaktavAtsalyAdbhajatyeva kadAcana ॥ 15 ॥
hk transliteration by Sanscript