首楞嚴義疏注經 6.202

6.202

優波尼沙陀因觀不淨白骨微塵，析色明空，塵色既盡，妙色密圓。今此揀云：色由妄想所結，染污真性，其體本麁、性是質礙，不能明徹，如何以此不明徹法而取圓通。

Upaniṣad, through contemplating the impurity of white bones and dust motes, analyzed form to clarify emptiness; when dust and form were exhausted, wonderful form became secretly perfect. Now this evaluation states: Form is congealed by false thinking, defiling the true nature; its substance is fundamentally coarse and its nature is obstructive, unable to be clear and penetrative. How could one use this non-clear and non-penetrative dharma to grasp perfect penetration?