Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 1

Sanskrit:

श्रीशुक उवाचसरस्वत्यास्तटे राजन्नृषय: सत्रमासत ।वितर्क: समभूत्तेषां त्रिष्वधीशेषु को महान् ॥ १ ॥

ITRANS:

śrī-śuka uvācasarasvatyās taṭe rājannṛṣayaḥ satram āsatavitarkaḥ samabhūt teṣāṁtriṣv adhīśeṣu ko mahān

Translation:

Śukadeva Gosvāmī said: Once, O King, as a group of sages were performing a Vedic sacrifice on the banks of the Sarasvatī River, a controversy arose among them as to which of the three chief deities is supreme.

Purport:

The three chief deities mentioned here are Lord Viṣṇu, Lord Brahmā and Lord Śiva.