大乘起信論廣釋卷第三．四．五 4.92

4.92

論。又亦無有至故說為用　釋曰。此明用無相也。此文三節。謂標徵釋用依體智。舉體即真故雖起用無相可得。佛具三身昞現用相。何故乃言無用相耶。若廢機感如來。唯是妙理本智最勝實義。更無應化生滅等相。但隨緣用。用即無用。如波即水。用而常寂。故說此身即是法身。唯如如智名法身等。故唯法身離施作等。雖真理妙智本來常湛。隨機感而應益用無邊。如水即波即寂常用。故隨眾生說為用等。

[Treatise:] Furthermore, there are no [marks of activity that can be grasped, because the Buddha-bodies are purely dharmakāyas, bodies of wisdom; they are the supreme reality, with no worldly truth or operations, and yet they perform activities because sentient beings see and hear them;] therefore it is said to be activity. [Commentary:] This clarifies that the activity is signless. This passage has three sections: stating, querying, and explaining that activity relies upon the cognition of substance. Adducing the substance as being identical to tathatā, although it arouses activity, no signs can be grasped. The Buddha possesses the three bodies, clearly manifesting the characteristics of activity; why then say there are no characteristics of activity? If one sets aside the responsiveness to sentient capacities, the Tathāgata is solely the wondrous principle, the fundamental cognition, and the supreme ultimate reality, with no further characteristics of arising and ceasing of responses and transformations. It is merely activity following conditions; activity is itself non-activity, just as waves are themselves water. Operating, it is eternally quiescent; therefore it is said that this body is precisely the dharmakāya. Solely suchness cognition is called the dharmakāya, and so on. Therefore, only the dharmakāya is free from deliberate operations and the like. Although the true principle and wondrous cognition are originally ever-serene, responsive to the capacities and inclinations of sentient beings, their beneficial activities are boundless. Just as water is itself waves and yet ever quiescent in its constant operation, so in accordance with sentient beings it is spoken of as activity and so forth.