首楞嚴義疏注經 4.16

4.16

此約世諦水火性異，難第一義性相俱融。下文答云「觀相元妄，無可指陳；觀性元真，唯妙覺明。妙覺明心先非水火，云何復問相陵滅義？」

This is based on the worldly truth of the distinct natures of water and fire to challenge the mutual fusion of nature and characteristic in the ultimate truth. The text below answers: 'Observing characteristics, they are fundamentally unreal, with nothing to point to; observing nature, it is fundamentally real, being solely the wondrous awakening brightness. Since the mind of wondrous awakening brightness is fundamentally neither water nor fire, why do you further ask about the meaning of mutual encroachment and extinction?'