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

Expressions researched:
"Outside of the three planetary systems (Svarga, Martya and Patala), the four yugas multiplied by one thousand comprise one day on the planet of Brahma. A similar period comprises a night of Brahma, in which the creator of the universe goes to sleep"

Srimad-Bhagavatam

SB Canto 3

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

SB 3.11.22, Translation and Purport

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

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