SB 1.6.31
antar bahis ca lokams trin
paryemy askandita-vratah
anugrahan maha-visnor
avighata-gatih kvacit
Translation Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Since then, by the grace of the almighty Visnu, I travel everywhere without restriction both in the transcendental world and in the three divisions of the material world. This is because I am fixed in unbroken devotional service of the Lord.
Purport Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As stated in the Bhagavad-gita, there are three divisions of the material spheres, namely the urdhva-loka (topmost planets), madhya-loka (midway planets) and adho-loka (downward planets). Beyond the urdhva-loka planets, that is to say above the Brahmaloka, are the material coverings of the universes, and above that is the spiritual sky, which is unlimited in expansion, containing unlimited self-illuminated Vaikuntha planets inhabited by God Himself along with His associates, who are all eternally liberated living entities. Sri Narada Muni could enter all these planets in both the material and spiritual spheres without restriction, as much as the almighty Lord is free to move personally in any part of His creation. In the material world the living beings are influenced by the three material modes of nature, namely goodness, passion and ignorance. But Sri Narada Muni is transcendental to all these material modes, and thus he can travel everywhere unrestricted. He is a liberated spaceman. The causeless mercy of Lord Visnu is unparalleled, and such mercy is perceived by the devotees only by the grace of the Lord. Therefore, the devotees never fall down, but the materialists, i.e., the fruitive workers and the speculative philosophers, do fall down, being forced by their respective modes of nature. The rsis, as above mentioned, cannot enter into the transcendental world like Narada. This fact is disclosed in the Narasimha Purana. Rsis like Marici are authorities in fruitive work, and rsis like Sanaka and Sanatana are authorities in philosophical speculations. But Sri Narada Muni is the prime authority for transcendental devotional service of the Lord. All the great authorities in the devotional service of the Lord follow in the footsteps of Narada Muni in the order of the Narada-bhakti-sutra, and therefore all the devotees of the Lord are unhesitatingly qualified to enter into the kingdom of God, Vaikuntha.