仁王護國般若波羅蜜多經疏 2.28

2.28

解曰：自下經文明其正智即有觀空，有十八也。此十八空，與《大般若》後四文別，如五十一，善現發問、世尊具答，略引彼經釋此文也。言內空者，內謂內法，即是眼耳鼻舌身意。此中眼由眼空，鼻等亦然，非常非壞，本性爾故。上言眼者，謂即眼處。由眼空者，眼無自性，眼處即空，餘皆悉矣。如《智度》論四十六說「若不習空必墮二邊，以空破有亦不著空。無我我所，本性爾故。」下文皆同，恐繁故略。言外空者，外謂外法，即是色聲香味觸法。此中色由色空，聲等亦爾。內外空者，謂內外法，內六根處、外六塵處。此中內六處由外六處空，外六處由內六處空，前別後總偏俱空故。從此第二明二諸空。

The commentary states: From here on, the sūtra text clarifies that correct cognition entails contemplating emptiness, of which there are eighteen. These eighteen emptinesses differ from the *Great Prajñāpāramitā* in their latter four items; as in fascicle 51, where Subhūti asks and the World-Honoured One answers in full, that sūtra is briefly cited here to explain this text. As for "internal emptiness," "internal" refers to internal phenomena, namely the eye, ear, nose, tongue, body, and mind. Here, the eye is empty through the eye, and the nose and others are also like this, being neither permanent nor destroyed, because their fundamental nature is so. Above, "eye" refers to the eye sense field. "Empty through the eye" means that the eye lacks intrinsic nature, and the eye sense field is itself empty; the rest are all like this. As the *Mahāprajñāpāramitopadeśa*, fascicle 46, states: "If one does not practice emptiness, one will surely fall into the two extremes; using emptiness to refute existence, one also does not cling to emptiness. There is no self and no mine, because their fundamental nature is so." The texts below are all the same, and are omitted for fear of verbosity. As for "external emptiness," "external" refers to external phenomena, namely form, sound, smell, taste, touch, and mental phenomena. Here, form is empty through form, and sound and the others are also like this. As for "internal-and-external emptiness," it refers to internal and external phenomena: the internal six sense bases and the external six sense objects. Here, the internal six sense fields are empty through the external six sense fields, and the external six sense fields are empty through the internal six sense fields, because the former are distinct while the latter are collective, and both individually and together are empty. Next is the second [part], clarifying the various two emptinesses.