तद्वा एतदक्षरं गार्ग्यदृष्टं द्रष्ट्रश्रुतँश्रोत्रमतं मन्त्रविज्ञातं विज्ञातृ नान्यदतो-ऽस्ति द्रष्टृ नान्यदतोऽस्ति श्रोतृ नान्यद-तोऽस्ति मन्तृ नान्यदतोऽस्ति विज्ञात्रे-तस्मिन्नु खल्वक्षरे गार्ग्याकाश ओतश्चप्रोतश्चेति ॥ ११ ॥
In plain words
This, Gārgī, is the Imperishable. It is never seen, yet it is the one who sees. It is never heard, yet it is the one who hears. It is never thought about, yet it is the one who thinks. It is never known as an object, yet it is the one who knows. Nothing else does the seeing, the hearing, the thinking, the knowing -- only this. And in this very Imperishable, Gārgī, space itself is woven, through and through.
Close to the Sanskrit
This, verily, Gārgī, is that Imperishable: unseen but the seer, unheard but the hearer, unthought but the thinker, unknown but the knower. There is nothing else that sees but this, nothing else that hears but this, nothing else that thinks but this, nothing else that knows but this. In this Imperishable, verily, Gārgī, ether is woven, crosswise and lengthwise.