SB 2.2.24
vaisvanaram yati vihayasa gatah
susumnaya brahma-pathena socisa
vidhuta-kalko ’tha harer udastat
prayati cakram nrpa saisumaram
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King, when such a mystic passes over the Milky Way by the illuminating Susumna to reach the highest planet, Brahmaloka, he goes first to Vaisvanara, the planet of the deity of fire, wherein he becomes completely cleansed of all contaminations, and thereafter he still goes higher, to the circle of Sisumara, to relate with Lord Hari, the Personality of Godhead.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The polar star of the universe and the circle thereof is called the Sisumara circle, and therein the local residential planet of the Personality of Godhead (Ksirodakasayi Visnu) is situated. Before reaching there, the mystic passes over the Milky Way to reach Brahmaloka, and while going there he first reaches Vaisvanara-loka, where the demigod controls fire. On Vaisvanara-loka the yogi becomes completely cleansed of all dirty sins acquired while in contact with the material world. The Milky Way in the sky is indicated herein as the way leading to Brahmaloka, the highest planet of the universe.