首楞嚴義疏注經 2.174

2.174

阿難問意，前對八境，權指妄見有無還義，因是得識本真元性不生不滅，為復只此表知性常、為更有義別得真妄？故云云何得知等。

The purport of Ānanda's question: earlier, in contrast to the eight sensory objects, he provisionally pointed out that false seeing has the meaning of having nowhere to return, and because of this, one is able to recognize that the original true, fundamental nature is unborn and unceasing. Is it merely this that indicates and reveals the permanence of the nature, or are there further meanings to distinguish between the true and the false? Hence he asks: 'how can I know', etc.