淨名經集解關中疏 1.519

1.519

佛身無為。不墮諸數　四明有為之身。四相所遷數也。佛身無生離生滅相常也。肇曰。法身無為而無不為。無不為故現身有病。無為故不墮有數也。

"The Buddha's body is unconditioned; it does not fall into any enumerated categories." Fourth, explaining the conditioned body, which is subject to the shifting count of the four characteristics. The Buddha's body is unborn, free from the characteristics of arising and ceasing—it is permanence. Sengzhao says: "The dharmakāya is unconditioned, yet there is nothing it does not do. Because there is nothing it does not do, it manifests a body that has illness. Because it is unconditioned, it does not fall into conditioned categories."