華嚴一乘教義分齊章 1.5

1.5

初中二：一、性海果分，是不可說義。何以故？不與教相應故，則十佛自境界也。故《地論》云：因分可說，果分不可說者是也。

Within the first, there are two aspects: first, the fruition aspect of the nature-ocean, which is an ineffable meaning. Why? Because it does not correspond to teaching; it is the self-realm of the ten buddhas. Therefore the Daśabhūmika-śāstra states: 'The causal aspect can be explained; the fruition aspect cannot be explained.' This is what it refers to.