妙法蓮華經玄義 7.14

7.14

此病若實者，應病法亦病。秖為應病非實，非實故，應身無病，法身亦無病。又若應身現病少，當知法身益亦少。若能應身現病廣，法身益亦廣也。

If this illness were real, then if the response body were ill, the dharma-kāya would also be ill. It is simply that the illness of the response body is not real; because it is not real, the response body has no illness, and the dharma-kāya also has no illness. Moreover, if the response body manifests little illness, one should know that the benefit to the dharma-kāya is also small. If the response body can manifest widespread illness, the benefit to the dharma-kāya is also vast.