法華義疏 3.156

3.156

就文為兩：一、標止言，二、釋止言。初如文。「所以者何」下，第二、釋止言，為二：初、明法妙，眾生不解，故不可言。次、明唯佛能解，故不須言。不言之意唯此兩也。

In the text there are two parts: first, marking the stopping of speech; second, explaining the stopping of speech. The first is as in the text. From “Why is this?” onwards, secondly, explaining the stopping of speech, has two parts: first, explaining that the Dharma is marvelous and sentient beings do not understand, so it cannot be spoken; second, explaining that only buddhas can understand, so there is no need to speak. The intention of not speaking consists solely of these two.