Who are you?

Reminded me of a Upanishad, I looked up a couple verses from the Katha Upanishad

“Nachiketa said: ‘that which you see as other than righteousness and unrighteousness, other than all this cause and effect, other than what has been and what is to be - tell me That”

“When the soul, identified with the body and dwelling in it, is torn away from the body, is freed from it, what then remains? This, verily, is That”

“As pure water poured into pure water becomes one with it, so also, O Gautama, does the Self of the sage who knows.”