首楞嚴義疏注經 2.402

2.402

若汝執言，雖然見暗只名不見，以不見明故，此牒計也。次即破云，今雖見明，亦合名為不見，以不見暗故。若立見明為見，見暗亦合名見；若立見暗為不見，見明亦合名不見，故云俱名不見也。

If you cling to the assertion that although seeing darkness, it is only called not seeing because one does not see light—this takes up his clinging. Next, it is immediately refuted: now, although seeing light, it should also be called not seeing, because one does not see darkness. If you establish that seeing light is seeing, then seeing darkness should also be called seeing; if you establish that seeing darkness is not seeing, then seeing light should also be called not seeing. Hence it is said: "both would be called not seeing."