SB 7.9.32
nyasyedam atmani jagad vilayambu-madhye
sesetmana nija-sukhanubhavo nirihah
yogena milita-drg-atma-nipita-nidras
turye sthito na tu tamo na gunams ca yunkse
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O my Lord, O Supreme Personality of Godhead, after the annihilation the creative energy is kept in You, who appear to sleep with half-closed eyes. Actually, however, You do not sleep like an ordinary human being, for You are always in a transcendental stage, beyond the creation of the material world, and You always feel transcendental bliss. As Karanodakasayi Visnu, You thus remain in Your transcendental status, not touching material objects. Although You appear to sleep, this sleeping is distinct from sleeping in ignorance.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As explained very clearly in the Brahma-samhita (5.47):
yah karanarnava-jale bhajati sma yoga-
nidram ananta-jagad-anda-sa-roma-kupah
adhara-saktim avalambya param sva-murtim
govindam adi-purusam tam aham bhajami
“I worship the primeval Lord Govinda, who lies down in the Causal Ocean in His plenary portion as Maha-Visnu, with all the universes generating from the pores of hair on His transcendental body, and who accepts the mystic slumber of eternity.” The adi-purusa, the original Supreme Personality of Godhead — Krsna, Govinda — expands Himself as Maha-Visnu. After the annihilation of this cosmic manifestation, He keeps Himself in transcendental bliss. The word yoga-nidram is used in reference to the Supreme Personality of Godhead. One should understand that this nidra, or sleep, is not like our nidra in the mode of ignorance. The Lord is always situated in transcendence. He is sac-cid-ananda — eternally in bliss — and thus He is not disturbed by sleep like ordinary human beings. It should be understood that the Supreme Personality of Godhead is in transcendental bliss in all stages. Srila Madhvacarya concisely states that the Lord is turya-sthitah, always situated in transcendence. In transcendence there is no such thing as jagarana-nidra-susupti — wakefulness, sleep and deep sleep.
The practice of yoga is similar to the yoga-nidra of Maha-Visnu. Yogis are advised to keep their eyes half closed, but this state is not at all one of sleep, although imitation yogis, especially in the modern age, manifest their so-called yoga by sleeping. In the sastra, yoga is described as dhyanavasthita, a state of full meditation, but this is meditation upon the Supreme Personality of Godhead. Dhyanavasthita-tad-gatena manasa: the mind should always be situated at the lotus feet of the Lord. Yoga practice does not mean sleeping. The mind should always be actively fixed at the lotus feet of the Lord. Then one’s practice of yoga will be successful.