All worlds, O Arguna! up to the world of Brahman, are (destined) to return. But, O son of Kunti! after attaining to me, there is no birth again. Those who know a day of Brahman to end after one thousand ages, and the night to terminate after one thousand ages, are the persons who know day and night. On the advent of day, all perceptible things are produced from the unperceived; and on the advent of night they dissolve in that same (principle) called the unperceived.