請觀音經疏 1.8

1.8

問：俗諦何獨開為二觀耶？答：俗境有麁細，故開為二。又問：俗有麁細為二觀，真亦淺深亦應二觀。答：俗是事，故得為二。真是理，理則無二，是故不開。

Question: Why is conventional truth alone opened into two contemplations? Answer: Because conventional objects have coarse and subtle [aspects], it is therefore opened into two. Another question: If the conventional has coarse and subtle [aspects] and forms two contemplations, ultimate truth also has shallow and deep [aspects], so it should also form two contemplations. Answer: The conventional pertains to phenomena; therefore, it can form two. Ultimate [truth] pertains to principle; principle is non-dual, and therefore it is not opened.