Garudapurana 3.29.8

3.29.8

indropi vāyukaramarditavāyukūṭabinduṃ ca prāśya śirasi hyasahiṣṇumānaḥ /
bhāgīrathī haripadāṅkamiti sma nityaṃ jānanmahāparamabhāgavatapradhānaḥ /
bhaktyā ca khinnahṛdayaḥ paramādareṇa dhṛtvā svamūrdhni paramo hyaśivaḥ śivo 'bhūt //

Even Indra, having drunk the drop of the wind-mass struck by the hand of the wind, and having an intolerant mind on his head, / knowing always that the Bhāgīrathī is marked with Hari's foot, as the foremost of the great supreme devotees of the Lord, / with a heart melting with devotion, holding her upon his head with the highest reverence, that supreme inauspicious one became Śiva [the auspicious one].