首楞嚴義疏注經 4.603

4.603

聞性不動其猶鏡明，聲之生滅正如影像，豈由影像有去有來，令其鏡明為生為滅？故下文云「音聲性動靜，聞中為有無，無聲號無聞，非實聞無性，聲無既無滅，聲有亦非生，生滅二圓離，是則常真實。」

The nature of hearing is unmoving, like the brightness of a mirror; the arising and ceasing of sound is just like a reflected image. How could the coming and going of an image cause the mirror's brightness to arise or perish? Therefore, the text below says: "The nature of sounds is movement and stillness, / Being present or absent within hearing. / When there is no sound, it is called 'no hearing,' / Not that the nature of hearing is truly absent. / When sound is absent, there is already no perishing; / When sound is present, neither is it an arising. / Arising and ceasing both completely abandoned, / This then is the constant and real."