大毘盧遮那成佛經疏 11.19

11.19

「祕密主！一切世界諸現在等如來、應、正等覺，通達方便波羅蜜多，彼如來知一切分別本性空，以方便波羅蜜多力故，而於無為以有為為表。展轉相應，而為眾生示現遍法界」者，謂無為之果，而以有為方便能成此事，不可思議。現在未來過去三世佛，皆以通達方便波羅蜜故，而說此法一也。舉三世佛，欲明同以此入也。雖復設此有為方便，然即了此分別之法本性常空。如是因緣起法，離於生滅、斷常、一異、去來，但如幻化，不異中道。若捨離此而求無為別體，不可得也，以無為之性即不異有為。了達如是甚深緣起法故，能以此有為即成無為之果也。是故一切三世如來以方便力故，雖證法界，而能從此無為無作本體之果，而以有為作諸眷屬。如大日如來於此自證之德，以加持力故，而於無為以有為為表者，本性無所為，因有所為而能成無為也。展轉相應者，未持誦時性本不淨，由持誦故便得清淨，能度眾生也。則現不清淨身，復為他作清淨因緣，名展轉相應也，還從無為生有為為表也。故現十世界微塵金剛菩薩，一一以真言門引接眾生，皆令得至無為之果是也。以此方便遍於法界，普應一切眾生，令得義利也。

As for "'Lord of Secrets! All presently existing Tathāgatas, Arhats, and Samyaksaṃbuddhas of all worlds have mastered the pāramitā of upāya. Those Tathāgatas know that all conceptual differentiations are by nature empty; by the power of the pāramitā of upāya, they express the unconditioned through the conditioned. Mutually corresponding, they manifest throughout the dharmadhātu for the sake of sentient beings'": this means that by using conditioned upāya for the sake of the unconditioned fruit, one can accomplish this matter, which is inconceivable. The buddhas of the three times—present, future, and past—all master the pāramitā of upāya, and therefore this teaching they expound is one and the same. Citing the buddhas of the three times is intended to clarify that they all enter through this together. Although they set forth these conditioned upāyas, they fully realize that the fundamental nature of these conceptual dharmas is eternally empty. Such dharmas arising from causes and conditions are free from arising and ceasing, annihilation and permanence, oneness and difference, coming and going; they are merely like illusions and transformations, not different from the Middle Way. If one abandons this to seek a separate substance of the unconditioned, it cannot be found, because the nature of the unconditioned is not different from the conditioned. Fully understanding such profound dharmas of dependent origination, one can use this conditioned to directly accomplish the unconditioned fruit. Therefore, by the power of upāya, although all Tathāgatas of the three times realize the dharmadhātu, from this unconditioned and non-active fundamental fruit, they use the conditioned to make retinues. Just as Mahāvairocana Tathāgata, in this virtue of his own realization, through the power of adhiṣṭhāna, expresses the unconditioned through the conditioned: the fundamental nature is inactive, but by means of action one is able to accomplish the unconditioned. 'Mutually corresponding' means that before recitation, one's nature is fundamentally impure; by reciting, one attains purity and can deliver sentient beings. Thus manifesting an impure body again serves as a cause and condition of purity for others; this is called 'mutually corresponding,' and again from the unconditioned arises the conditioned as an expression. Therefore, manifesting vajra-bodhisattvas as numerous as dust motes in ten worlds, each guiding and receiving sentient beings through the mantra gateway to bring them all to the unconditioned fruit—this is it. Pervading the dharmadhātu with this upāya, they universally respond to all sentient beings, causing them to attain benefit.