大方廣圓覺修多羅了義經略疏 2.418

2.418

由前以靜澄心，諸念不起，心合靜源，體非分別，故見分別之識煩勞動擾。苦自是識，則不能見識，如眼不自見。今由念澄智顯，故覺識也。

Because of previously clarifying the mind through stillness, thoughts do not arise; the mind unites with the source of stillness, its essence being non-conceptual; thus one sees that the conceptualizing consciousness is troublesome and agitating. If one were [immersed in] consciousness itself, one could not see consciousness, just as an eye does not see itself. Now, because thoughts are clarified and wisdom is revealed, one perceives consciousness.