Srimad Bhagavatam Canto 03, Chapter 08, Text 17

SB 3.8.17

tasmad yuganta-svasanavaghurna-
 jalormi-cakrat salilad virudham
upasritah kañjam u loka-tattvam
 natmanam addhavidad adi-devah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Lord Brahma, situated in that lotus, could not perfectly understand the creation, the lotus or himself. At the end of the millennium the air of devastation began to move the water and the lotus in great circular waves.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Lord Brahma was perplexed about his creation, the lotus and the world, even though he tried to understand them for one millennium, which is beyond calculation in the solar years of human beings. No one, therefore, can know the mystery of the creation and cosmic manifestation simply by mental speculation. The human being is so limited in his capacity that without the help of the Supreme he can hardly understand the mystery of the will of the Lord in terms of creation, continuance and destruction.
Srimad Bhagavatam Canto 03, Chapter 08, Text 16
Srimad Bhagavatam Canto 03, Chapter 08, Text 18