Srimad Bhagavatam Canto 10, Chapter 13, Text 41

SB 10.13.41

yavanto gokule balah
sa-vatsah sarva eva hi
mayasaye sayana me
nadyapi punar utthitah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Lord Brahma thought: Whatever boys and calves there were in Gokula, I have kept them sleeping on the bed of my mystic potency, and to this very day they have not yet risen again.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
For one year Lord Brahma kept the calves and boys lying down in a cave by his mystic power. Therefore when Brahma saw Lord Krsna still playing with all the cows and calves, he began trying to reason about what was happening. “What is this?” he thought. “Maybe I took those calves and cowherd boys away but now they have been taken from that cave. Is this what has happened? Has Krsna brought them back here?” Then, however, Lord Brahma saw that the calves and boys he had taken were still in the same mystic maya into which he had put them. Thus he concluded that the calves and cowherd boys now playing with Krsna were different from the ones in the cave. He could understand that although the original calves and boys were still in the cave where he had put them, Krsna had expanded Himself and so the present demonstration of calves and boys consisted of expansions of Krsna. They had the same features, the same mentality and the same intentions, but they were all Krsna.
Srimad Bhagavatam Canto 10, Chapter 13, Text 40
Srimad Bhagavatam Canto 10, Chapter 13, Text 42