Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 18

Sanskrit:

क एष योऽसावहमब्जपृष्ठएतत्कुतो वाब्जमनन्यदप्सु ।अस्ति ह्यधस्तादिह किञ्चनैत-दधिष्ठितं यत्र सता नु भाव्यम् ॥ १८ ॥

ITRANS:

ka eṣa yo ’sāv aham abja-pṛṣṭhaetat kuto vābjam ananyad apsuasti hy adhastād iha kiñcanaitadadhiṣṭhitaṁ yatra satā nu bhāvyam

Translation:

Lord Brahmā, in his ignorance, contemplated: Who am I that am situated on the top of this lotus? Wherefrom has it sprouted? There must be something downwards, and that from which this lotus has grown must be within the water.

Purport:

The subject matter of the speculations of Brahmā in the beginning regarding the creation of the cosmic manifestation is still a subject matter for mental speculators. The most intelligent man is he who tries to find the cause of his personal existence and that of the whole cosmic creation and thus tries to find the ultimate cause. If his attempt is properly executed with penances and perseverance, it is sure to be crowned with success.