After saying this, Bhagīratha satisfied Lord Śiva by performing austerities. O King Parīkṣit, Lord Śiva was very quickly satisfied with Bhagīratha.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
इत्युक्त्वा स नृपो देवं तपसातोषयच्छिवम् । कालेनाल्पीयसा राजंस्तस्येशः समतुष्यत
ityuktvā sa nṛpo devaṃ tapasātoṣayacchivam | kālenālpīyasā rājaṃstasyeśaḥ samatuṣyata
SB 9.9.8