Shivapurana 3.36.9

Śivapurāṇa (complete text) 3.36.9

tasya stutyā ca tapasā santuṣṭaḥ śaṅkaraḥ prabhuḥ |
varaṃ brūhīti covāca droṇaṃ taṃ bhaktavatsalaḥ ||