यथोदकं शुद्धे शुद्धमासिक्तं तादृगेव भवति ।
एवं मुनेर्विजानत आत्मा भवति गौतम ॥ १५ ॥

yathodakaṃ śuddhe śuddhamāsiktaṃ tādṛgeva bhavati ।
evaṃ munervijānata ātmā bhavati gautama ॥ 15 ॥

15. As water pure poured into pure becomes the same only, so the atman of the thinker who knows thus, becomes; Oh Gautama.

Shankara’s Commentary:

But how becomes the atman of a thinker who has acquired knowledge, whose perception of difference due to conditions has been destroyed, and who knows the atman pure, dense with knowledge unalloyed, and one without a second, is explained. As water pure poured into pure becomes of the same quality, not otherwise, the atman also of the thinker becomes the same, Oh Gautama. Therefore, leaving the perception of difference induced by bad logic and the erroneous notion of no-here-after, the perception of the one-ness of the atman inculcated by the Vedas, a better well-wisher than thousands of mothers and fathers should be anxiously respected by those whose pride has been quelled.


॥ इति काठकोपनिषदि द्वितीयाध्याये प्रथमा वल्ली ॥

|| iti kāṭhakopaniṣadi dvitīyādhyāye prathamā vallī ||

Here ends the Fourth Part.