Srimad Bhagavatam Canto 12, Chapter 11, Text 50

SB 12.11.50

evam hy anadi-nidhano
 bhagavan harir isvarah
kalpe kalpe svam atmanam
 vyuhya lokan avaty ajah
 
Translation: 
 
For the protection of all the worlds, the Supreme Personality of Godhead Hari, who is unborn and without beginning or end, thus expands Himself during each day of Brahma into these specific categories of His personal representations.
 
Purport: 
 
Thus end the purports of the humble servants of His Divine Grace A.C. Bhaktivedanta Swami Prabhupada to the Twelfth Canto, Eleventh Chapter, of the Srimad-Bhagavatam, entitled “Summary Description of the Mahapurusa.”
Srimad Bhagavatam Canto 12, Chapter 11, Text 49
Srimad Bhagavatam Canto 12, Chapter 11 Narration