Katha Upanishad Verse 2.2.11

The sun is the “eye of the world” and illuminates both the pure and the impure, yet remains untainted by any stains it reveals. Similarly, the one internal Atman of all living things remains unaffected by the grief and suffering of the world, being external to all manifested phenomena.

Sanskrit Verse

सूर्यो यथा सर्वलोकस्य चक्शुर्न लिप्यते चाक्शुषैर्बाह्यदोषैः ।
एकस्तथा सर्वभूतान्तरात्मा न लिप्यते लोकदुःखेन बाह्यः ॥ ११ ॥

Transliteration

sūryo yathā sarvebehasya cakśurna lipyate cākśuṣairbāhyadoṣaiḥ |
ekastathā sarvebhūtāntarātmā na lipyate lokaduḥkhena bāhyaḥ || 11 ||

Translation

As the sun, the eye of all the world, is not tainted with the stains in external objects seen by the eyes, so, the one internal atman of all living things is not tainted with the world’s grief, being external to it.