Shiva Purana
वृषेश्वरोऽपि भगवाच्छंकरो भक्तवत्सलः ॥ इत्थं कृत्वा देवकार्यं जगाम स्वगिरीश्वरम् ॥ ३६ ॥
Lord Śiva, favourably disposed towards his devotees, returned to his mountain after carrying out the task of the gods in the guise of a bull.
english translation
vRSezvaro'pi bhagavAcchaMkaro bhaktavatsalaH ॥ itthaM kRtvA devakAryaM jagAma svagirIzvaram ॥ 36 ॥
hk transliteration by Sanscript