維摩經玄疏 2.94

2.94

Next, regarding the contemplation of the signless samādhi: one contemplates the unarisen true mark as not having signs, unlike the existence of signs of jars and basins in a dark room; as not lacking signs, unlike the absence of the nature of curd within milk; as neither having signs nor lacking signs, unlike the wise seeing emptiness and non-emptiness; and as not neither having signs nor lacking signs, for grasping and attaching to that is the talk of foolishness. If one does not grasp fixed signs of the four extremes, this is using the signless samādhi to enter the true mark. If so, how could it be wholly identical to the Dilun masters who use 'inherently existing buddha-nature, like jars and basins in a dark room'? Nor is it wholly identical to the Sanlun masters who refute 'the nature of curd in milk as being completely and thoroughly cleared away, having no nature at all'!