त्रिलोक्या युगसाहस्रं बहिराब्रह्मणो दिनम् ।
तावत्येव निशा तात यन्निमीलति विश्वसृक् ॥२२॥

tri-lokyÄ yuga-sÄhasraá¹
bahir Äbrahmaṇo dinam
tÄvaty eva niÅ›Ä tÄta
yan nimīlati viśva-sṛk

 tri-lokyÄḥ - of the three worlds; yuga - the four yugas; sÄhasram - one thousand; bahiḥ - outside of; Äbrahmaṇaḥ - up to Brahmaloka; dinam - is a day; tÄvatÄ« - a similar (period); eva - certainly; niÅ›Ä - is night; tÄta - O dear one; yat - because; nimÄ«lati - goes to sleep; viÅ›va-sá¹›k - BrahmÄ.


Text

Outside of the three planetary systems [Svarga, Martya and PÄtÄla], the four yugas multiplied by one thousand comprise one day on the planet of BrahmÄ. A similar period comprises a night of BrahmÄ, in which the creator of the universe goes to sleep.

Purport

When BrahmÄ goes to sleep in his nighttime, the three planetary systems below Brahmaloka are all submerged in the water of devastation. In his sleeping condition, BrahmÄ dreams about the GarbhodakaÅ›ÄyÄ« Viṣṇu and takes instruction from the Lord for the rehabilitation of the devastated area of space.