upaniṣat kahe tāṅre brahma sunirmala
tāṅhāra-His; aṅgera -of the body; śuddha -pure; kiraṇa -of rays; maṇḍala -realm; upaniṣat -the Upaniṣads; kahe -say; tāṅre -unto that; brahma -Brahman; su-nirmala -transcendental.
What the Upaniṣads call the transcendental, impersonal Brahman is the realm of the glowing effulgence of the same Supreme Person.
"In the spiritual realm, beyond the material covering, is the unlimited Brahman effulgence, which is free from material contamination. That effulgent white light is understood by transcendentalists to be the light of all lights. In that realm there is no need of sunshine, moonshine, fire or electricity for illumination. Indeed, whatever illumination appears in the material world is only a reflection of that supreme illumination. That Brahman is in front and in back, in the north, south, east and west, and also overhead and below. In other words, that supreme Brahman effulgence spreads throughout both the material and spiritual skies."