維摩經玄疏 1.132

1.132

今明以此四不可說有因緣故，以四悉檀而為說法，即是「聖說」。此四種四諦，並是三乘聖人證法，非是凡夫之所能知，故不可說也。如為生盲，說白色相，而彼生盲，終不能見。以不見故，故不可說；不可說故，名「聖默然」。

We now clarify that because these four ineffables have causes and conditions, preaching the Dharma by means of the four siddhāntas is precisely the 'noble preaching.' These four kinds of four noble truths are all dharmas realized by the sages of the three vehicles, not what ordinary beings are capable of knowing; hence they are ineffable. It is like explaining the appearance of the color white to one born blind: that person born blind ultimately cannot see it. Because they do not see it, it is ineffable; because it is ineffable, it is called 'noble silence.'