Shiva Purana

siva.sh/siva-purana/kotirudra-samhita/3/31

तत्सर्वमुभयोर्दृष्ट्वा समूचुर्भजनं वरम्।। पूर्वैश्च ऋषिभिश्चैव दुष्करं तु तपः कृतम् ।। ३१ ।।

sanskrit

On seeing their performance some said “Her service is better.” Others said “Difficult penances had been performed by sages of yore but nothing like Dadhīci’s penance was ever performed by any”.

english translation

tatsarvamubhayordRSTvA samUcurbhajanaM varam|| pUrvaizca RSibhizcaiva duSkaraM tu tapaH kRtam || 31 ||

hk transliteration by Sanscript