大毘盧遮那成佛經疏 7.8.7

7.8.7

且如娑哆也是諦義，是故經云「娑字門，一切諸法諦不可得。 」又娑哆是著義，是故供養法中云「娑字門，一切諸法無染著。 」又如婆嚩是有義，是故經云「婆字門，一切諸法有不可得。 」又婆嚩娜是觀義，是故供養法中云「婆字門，一切法離諸觀。 」餘皆倣此。 所以《大品經》及《花嚴．入法界品》皆說四十二字門。 《涅槃．文字品》、《文殊所問經》、《大集．陀羅尼自在王品》各釋悉曇字母，與此經所說其義或同。 若得此意，則諸經冷然懸會，無所違妨也。 復次一一字門皆言不可得者，為明中道義故。 今且寄車字門說之。 如觀鏡中面像，以本質為因、淨鏡為緣，有影復現為見為是所生之法。 妍蚩之相現前不謬故名為有，以種種方便推求都不可得是名為空，此有此空皆不出鏡體即一名中。 三相不同而同、不異而異，是故世間論者不能思議。 今真言門亦爾，以觀心為因、三密為緣，普門海會現前不謬故名為有，以種種門推求都不可得是名為空，此有此空皆不出法界故說為中。 三諦不同而同、不異而異，一切方便乘人不能思議。 餘法門例皆如此，不可遍舉也。

For instance, satya means truth; therefore the sūtra says: "The syllable SA gateway, because the truth of all dharmas is unobtainable." Also, sakta means attachment; therefore the worship ritual says: "The syllable SA gateway, all dharmas are free from defiling attachment." Again, for example, bhava means existence; therefore the sūtra says: "The syllable BHA gateway, because the existence of all dharmas is unobtainable." Also, bhāvanā means contemplation; therefore the worship ritual says: "The syllable BHA gateway, all dharmas are free from all contemplations." The rest are all modelled on this. Therefore the Larger Prajñāpāramitā Sūtra and the "Entry into the Dharmadhātu Chapter" of the Avataṃsaka both expound forty-two syllable gateways. The "Letters Chapter" of the Nirvāṇa, the Sūtra of Mañjuśrī's Questions, and the "Dhāraṇī-īśvararāja Chapter" of the Mahāsaṃnipāta each explain the siddham syllabary, and their meanings are sometimes identical to what this sūtra expounds. If one grasps this intention, the various sūtras will lucidly and harmoniously converge without any obstruction. Furthermore, that each syllable gateway is said to be unobtainable is to clarify the meaning of the Middle Way. For now, let us explain it by drawing upon the syllable CA gateway. Just as when looking at the reflection of a face in a mirror, taking the original face as the cause and the clean mirror as the condition, the reflection appears again as visible, which is the produced dharma. Because the features of beauty and ugliness appear right before one without error, it is called existence; because seeking it through various expedients it is entirely unobtainable, it is called emptiness; and because neither this existence nor this emptiness ever departs from the mirror's substance itself, it is called the Middle. These three marks are the same yet not the same, different yet not different; therefore worldly debaters cannot conceive of it. Now the mantra gateway is also like this: taking the contemplation of the mind as the cause and the three mysteries as the condition, the ocean-like assembly of the universal gateway appears right before one without error, hence it is called existence; because seeking it through various gateways it is entirely unobtainable, it is called emptiness; and because neither this existence nor this emptiness ever departs from the dharmadhātu, it is spoken of as the Middle. The three truths are the same yet not the same, different yet not different, inconceivable to people of all expedient vehicles. The other Dharma gateways are all like this and cannot be cited exhaustively.