यद्वै तन्न पश्यति पश्यन्वै तन्न पश्यतिन हि द्रष्टुर्द्दृष्टेर्विपरिलोपो विद्यतेऽविना-शित्वात् ।न तु तद्द्वितीयमस्ति ततोऽन्य-द्विभक्तं यत्पश्येत् ॥ २३ ॥
In plain words
When he seems not to see in that state, he is still seeing—seeing is simply what he is, and it can never stop, because it can never die. There just isn't a second thing out there, separate from him, left for him to see.
Close to the Sanskrit
That which he does not see there—verily, seeing, he does not see there; for there is no loss of the seer's seeing, because it is imperishable. But there is not a second thing, other than that, separate, which he could see.