Chāndogya Upaniṣad 3.13.7

3.13.7

atha yad ataḥ paro divo jyotir dīpyate viśvataḥpṛṣṭheṣu sarvataḥpṛṣṭheṣv anuttameṣūttameṣu lokeṣv idaṃ vāva tad yad idam asminn antaḥ puruṣe jyotiḥ \
tasyaiṣā dṛṣṭir yatraitad asmiñ charīre saṃsparśenoṣṇimānaṃ vijānāti \
tasyaiṣā śrutir yatraitat karṇāv apigṛhya ninadam iva nadathur ivāgner iva jvalata upaśṛnoti \
tad etad dṛṣṭaṃ ca śrotaṃ cety upāsīta \
cakṣuṣyaḥ śruto bhavati ya evaṃ veda ya evaṃ veda \\313.7\

7. Now, the light which shines higher than this heaven, on the backs of all, on the backs of everything, in the highest worlds, than which there are no higher—verily, that is the same as this light which is here within a person.

There is this seeing of it— when one perceives by touch this heat here in the body. There is this hearing of it—when one closes his ears and hears as it were a sound, as it were a noise, as of a fire blazing. One should reverence that light as something that has been seen and heard. He becomes one beautiful to see, one heard of in renown, who knows this—yea, who knows this!