Shiva Purana
एवं मया कृतं तत्र तपोत्युग्रं मुनीश्वर ॥ तथापि शंकरो मह्यं न प्रसन्नोऽभवन्मनाक् ॥ ४१ ॥
O great sage, thus I performed a severe penance there. Still Śiva was not even slightly pleased with me.
english translation
evaM mayA kRtaM tatra tapotyugraM munIzvara ॥ tathApi zaMkaro mahyaM na prasanno'bhavanmanAk ॥ 41 ॥
hk transliteration by Sanscript