大毘盧遮那成佛神變加持經 (Shubhakarasimha & Yixing 724) 2.11

2.11

They are the mantras of servant messengers and wrathful ones.

If they have the word namaḥ (“homage”), svāhā, and so on,

These are the marks of [mantras of] practitioners of quiescence

cultivating samādhi.

If they have the word śānta (“pacified”), the word viśuddha

(“purified”), and so on,

You should know that they are able to fulfill all wishes:

These are the mantras of Perfectly Awakened Ones, sons of the

Buddha, and world-saviors.

In the case of those expounded by śrāvakas, each single phrase

is set out;

Among these, those of pratyekabuddhas differ slightly again,

For their samādhi is different and purifies karma and [re]birth.

“Furthermore, Lord of Mysteries, these characteristics of mantras are not something created by all the buddhas, nor did they cause others to create them, nor would they rejoice [if others had created them]. Why? Because this is the Dharma-thusness of dharmas. Therefore, whether the Tathāgatas appear or whether the Tathāgatas do not appear, dharmas naturally abide thus. That is to say, mantras are naturally mantras. Lord of Mysteries, when an all-knowing one and all-seeing one who has accomplished full and perfect awakening appears in the world, he teaches various paths by this method; in accordance with various desires and the various mentalities of beings and by means of various words, various letters, various regional languages, and the various sounds of the destinies [of transmigratory existence], he teaches through empowerment the mantra path.

“Lord of Mysteries, what is the mantra path of the Tathāgatas? It is, namely, the empowering of these written letters. Lord of Mysteries, with the words of truth, the four noble truths, the four stations of mindfulness, the four supernatural faculties, the ten powers of a Tathāgata, the six pāramitās, the seven precious [limbs] of bodhi, the four Brahmic abodes, and the eighteen unshared qualities of a buddha that the Tathāgatas have accumulated and cultivated during immeasurable hundreds of thousands of koṭis of nayutas of eons—Lord of Mysteries, in short, with the Tathāgatas’ knowledge of an omniscient one, the power of the own-merit and knowledge of all the Tathāgatas, the power of the knowledge of their own vows, and the power of the empowerment of the entire Dharma realm, and in conformity with the varieties of beings, they reveal the mantra teachings.

“And what are the mantra teachings? They are: the gateway of the letter A, because all dharmas are originally unborn (ādyanutpāda: “original

non-arising”); the gateway of the letter Ka, because all dharmas are dissociated from action (kārya); the gateway of the letter Kha, because all dharmas are inapprehensible like empty space (kha); the gateway of the letter Ga, because all going (gati) is inapprehensible in all dharmas; the gateway of the letter Gha, because agglomeration (ghana: “compact [mass]”) is inapprehensible in all dharmas; the gateway of the letter Ca, because all dharmas are dissociated from all transiency (cyuti: “fall”); the gateway of the letter Cha, because shadows (chāyā) are inapprehensible in all dharmas; the