avyaktād vyaktayaḥ sarvāḥ prabhavantyahar-āgame
rātryāgame pralīyante tatraivāvyakta-sanjñake||18|| 

Meaning : At the beginning of Brahma’s day, all living beings come into existence from the unmanifest. At the coming of night, they dissolve back into the unmanifest again.