Night of Brahma

ब्रह्मा - naɪt əv ˈbrəhmɑː

A period of one kalpa or a thousand mahayugas during which creation is unmanifested. (1)

During the night of Brahma, all of creation withdraws into an unmanifest state. Souls that were still manifest and not liberated during the day withdraw from outward manifestation but persist in “seed” form. Following the night, they appear in manifest form during the day of Brahma. (2)

Although one may misconceive of the night of Brahma as a period of cosmic dissolution, it is actually a time of quiescence. It may be conceived of as a wintertime during which the seeds of creation lie dormant; although unmanifest, the forms of consciousness are particles of universal consciousness. The night of Brahma differs from the Absolute Unmanifest, which remains eternally untouched by the cycles of creation. (1)

References
  1. a b The Essence of the Bhagavad Gita, explained by Paramhansa Yogananda. Chapter 21, “Final Liberation.”
  2. Conversations with Yogananda, by Swami Kriyananda. Entry 91.