Shiva Purana

siva.sh/siva-purana/saturda-samhita/6/5

शक्रमुद्दिश्य स मुनिस्तपस्तेपे सुदुः सहम् ।। निश्चलात्मा शिलादाख्यो बहुकालं दृढव्रतः ।। ५ ।।

sanskrit

That sage Śilāda performed a severe penance with Indra in view, for a long time. His mind was steady and he was stead-fast in his activities.

english translation

zakramuddizya sa munistapastepe suduH saham || nizcalAtmA zilAdAkhyo bahukAlaM dRDhavrataH || 5 ||

hk transliteration by Sanscript