CHĀNDOGYA UPANISHAD · 3.13.7

अथ यद् अतः परो दिवो ज्योतिर् दीप्यते विश्वतःपृष्ठेषु सर्वतःपृष्ठेष्व् अनुत्तमेषूत्तमेषु लोकेष्व् इदं वाव तद् यद् इदम् अस्मिन्न् अन्तः पुरुषे ज्योतिः । ॥

atha yad ataḥ paro divo jyotir dīpyate viśvataḥpṛṣṭheṣu sarvataḥpṛṣṭheṣv anuttameṣūttameṣu lokeṣv idaṃ vāva tad yad idam asminn antaḥ puruṣe jyotiḥ । ॥

Now that light which shines above this heaven, higher than all, higher than everything, in the highest world, beyond which there are no other worlds, that is the same light which is within man. And of this we have this visible proof:

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)