Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 16
Sanskrit:
तस्यां स चाम्भोरुहकर्णिकाया-मवस्थितो लोकमपश्यमान: ।परिक्रमन् व्योम्नि विवृत्तनेत्र-श्चत्वारि लेभेऽनुदिशं मुखानि ॥ १६ ॥
ITRANS:
tasyāṁ sa cāmbho-ruha-karṇikāyāmavasthito lokam apaśyamānaḥparikraman vyomni vivṛtta-netraścatvāri lebhe ’nudiśaṁ mukhāni
Translation:
Brahmā, born out of the lotus flower, could not see the world, although he was situated in the whorl. He therefore circumambulated all of space, and while moving his eyes in all directions he achieved four heads in terms of the four directions.