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.”