"तत्त्वमसि" महावाक्योपदेशःThe teaching of the great saying "That thou art"
Verse 264
तत्त्वमसि महाप्राज्ञ हंसः सोऽहं विभावय । निर्ममो निरहङ्कारः स्वभावेन सुखं चर ॥ २६४ ॥
tattvamasi mahāprājña haṁsaḥ sō’haṁ vibhāvaya | nirmamō nirahaṅkāraḥ svabhāvēna sukhaṁ cara || 264 ||
Translation
"That thou art, great-minded one; contemplate: I am haṁsa, I am He. Free of 'mine', free of 'I', move through the world at your own nature, happy."
Word by word
- tat
- (tat) That
- tvam
- (tvam) thou
- asi
- art
- mahāprājña
- O great-minded one
- haṁsaḥ
- haṁsa
- sō
- (saḥ) He
- ahaṁ
- I am
- vibhāvaya
- contemplate
- nirmamō
- (nirmamaḥ) free of "mine"
- nirahaṅkāraḥ
- free of "I"
- svabhāvēna
- at your own nature
- sukhaṁ
- happy
- cara
- move
Meaning
The teaching of renunciation is the great saying of the Chāndogya Upaniṣad, "tat tvam asi", "That thou art": the Brahman known as the cause of the world, the commentary explains, you yourself are. "Haṁsaḥ so 'ham", "I am the swan, I am He", is the mantra of the breath read as identity with the Self. Then the life of the avadhūta in a line: without possessiveness (towards son and the rest, the commentary says) and without self-importance (the swelling of mind from learning and the like), he wanders "at his own nature", happy.

Commentary
Hariharānanda Bhāratī’s Sanskrit commentary, translated
To the question "what should the guru say into the disciple's right ear?", he says "tat tvam asi…" and the rest. O greatly wise one, great thinker: that, the supreme Brahman, well known as the cause of the world, you are. Therefore contemplate, consider: "I am He, the supreme Self; He is I." Moreover, free of "mine" (empty of the sense of ownership towards son and the rest), free of "I" (without the swelling of the mind that comes from learning and the like), move, go here and there, at your own nature, so that it is happy. The dropping of the initial a of "aham" is a seer's licence.