大毘盧遮那成佛經疏 3.33

3.33

「善解真言實義」者，如真言門。有種種真言、種種身印、種種本尊，乃至具緣供物一一支分，聲字形色諸相不同，隨事分別識其性類，知如是法寂災處用、如是法增益處用、如是法降伏處用，如持明藏蘇悉地等廣分別說。此是通達真言實義。所以然者？一一真言皆如來妙極之語也。如真言中有質多字，淺釋只名為心；若作深祕釋，質謂遮字帶三昧聲也。遮是無遷變義，無遷變即是佛性，佛性亦名般若波羅蜜，亦名首楞嚴三昧，是故定慧具足。多字是一切法如如解脫不可得義。若如是說心，乃名妙極之語也。復次如身印，左手是三昧義、右手是般若義，十指是十波羅蜜滿足義，亦是一切智五輪譬喻義。如本尊形，女是禪定、男是智慧，黃色是金剛身、白是大悲、赤是大慧、青是大空、黑是大力。乃至一切緣中，皆有第一實際義，豈可如文生解耶？若通達如是實義，乃應作阿闍梨，亦約三劫十地以明深行也。

Regarding "skillfully understanding the true meaning of mantras": this refers to the mantra gateway. There are various mantras, various mudrās, and various deities, down to each component of the requisite offerings, whose sounds, syllables, shapes, and colors have diverse marks; by discerning them according to circumstances and recognizing their natures and categories, one knows that such dharmas are used for pacification, such dharmas are used for enrichment, and such dharmas are used for subjugation, as explained at length in the *Vidyādharapiṭaka*, *Susiddhi*, and so forth. This is thoroughly penetrating the true meaning of mantras. Why is this so? Each and every mantra is the Tathāgata's wondrously ultimate speech. For example, in mantras there is the syllable *citta*; a shallow explanation merely calls it "mind", but if one gives a profound secret explanation, *ci* means the syllable *ca* carrying the sound of samādhi. *Ca* means the sense of being without alteration; being without alteration is none other than Buddha-nature, and Buddha-nature is also called prajñāpāramitā, and also called Śūraṅgama samādhi; therefore, concentration and wisdom are complete. The syllable *tta* is the sense of suchness, liberation, and unattainability of all dharmas. If one explains "mind" in this way, it is indeed called wondrously ultimate speech. Furthermore, as with mudrās: the left hand has the meaning of samādhi, the right hand has the meaning of prajñā, the ten fingers have the meaning of fulfilling the ten pāramitās, and also the metaphorical meaning of the five wheels of sarvajña. As with the form of deities: female represents meditation, male represents wisdom; yellow is the vajra body, white is mahākaruṇā, red is great wisdom, blue is great emptiness, and black is great power. Down to all conditions, all possess the ultimate truth; how could one merely generate understanding according to the literal text? If one thoroughly penetrates such true meanings, only then should one serve as an ācārya; this is also explained as profound practice in terms of the three kalpas and ten bhūmis.