Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 9
Sanskrit:
इष्ट्वाग्निजिह्वं पयसा पुरुषं यजुषां पतिम् ।निम्लोचत्यर्क आसीनमग्न्यगारे समाहितम् ॥ ९ ॥
ITRANS:
iṣṭvāgni-jihvaṁ payasāpuruṣaṁ yajuṣāṁ patimnimlocaty arka āsīnamagny-agāre samāhitam
Translation:
The sun was setting, and the sage was sitting in trance after offering oblations to the Supreme Personality of Godhead, Viṣṇu, whose tongue is the sacrificial fire.
Purport:
Fire is considered to be the tongue of the Personality of Godhead Viṣṇu, and oblations of grains and clarified butter offered to the fire are thus accepted by Him. That is the principle of all sacrifices, of which Lord Viṣṇu is the master. In other words, the satisfaction of Lord Viṣṇu includes the satisfaction of all demigods and other living beings.