首楞嚴義疏注經 10.220

10.220

明中虛者，圓明之理，即所觀識也。已滅生滅，故明中虛。非即是滅，故云非滅。色、受、想、行攝一切法，名為群化。永滅依，即明中虛也。此計空為所歸依處，即涅槃也。

'Voidness within the clarity' refers to the principle of perfect clarity, which is the consciousness being observed. Having already extinguished arising and ceasing, there is voidness within the clarity. It is not itself extinction, so it is said: 'not by extinguishing.' Form, feeling, conception, and volition subsume all dharmas and are termed 'the host of transformations.' 'Reliance on eternal extinction' refers to the voidness within the clarity. This is taking emptiness as the place of refuge, namely nirvāṇa.