仁王護國般若波羅蜜多經疏 2.139

2.139

解曰：實相非色故非見、非聲故非聞、非香味觸故非覺、非法塵故非知。從此第五文有兩對約廢詮明。

Explanation: The real mark is not form, hence it is not seen; not sound, hence it is not heard; not fragrance, taste, or touch, hence it is not sensed; not a mental object, hence it is not known. From here is the fifth; the text has two pairs explaining with reference to setting aside verbal explanation.