यद्वै तन्न मनुते मन्वानो वै तन्न मनुतेन हि मन्तुर्मतेर्विपरिलोपो विद्यतेऽविना-शित्वान्न तु तद्द्वितीयमस्ति ततोऽन्यद्वि-भक्तं यन्मन्वीत ॥ २८ ॥
In plain words
When he seems not to think in that state, he is still thinking—thought is simply what he is, and it can never stop, because it can never die. There is no second thing out there, apart from him, left for him to think about.
Close to the Sanskrit
That which he does not think there—thinking, indeed, he does not think there; for there is no loss of the thinker's thought, because it is imperishable. But there is not a second thing, other than that, separate, which he could think.