2.17 Tu, but  this word is used for distinguishing (reality) from unreality; tat viddhi, know That; to be avinasi, indestructible, by nature not subject to destruction; what? (that) yena, by which, by which Brahman called Reality; sarvam, all; idam, this, the Universe together with space; is tatam, pervaded, as pot etc. are pervaded by space. Na kascit, none; arhati, can; kartum, bring about; vinasam, the destruction, disappearance, nonexistence; asya, of this avyayasya, of the Immutable, that which does not undergo growth and depletion. By Its very nature this Brahman called Reality does not suffer mutation, because, unlike bodies etc., It has no limbs; nor (does It suffer mutation) by (loss of something) belonging to It, because It has nothing that is Its own. Brahman surely does not suffer loss like Devadatta suffering from loss of wealth. Therefore no one can bring about the destruction of this immutable Brahman. No one, not even God Himself, can destroy his own Self, because the Self is Brahman. Besides, action with regard to one's Self is self-contradictory.
Which, again, is that 'unreal' that is said to change its own nature? This is being answered: