大般涅槃經集解 7.118

7.118

案道生曰：譬無常等五門觀也。僧亮曰：更思治門，斷思惟結也。法瑤曰：辛苦等味，譬無常等觀也。前云醫方伎藝，談化之始也。此言辛苦，敘教之終也。一段事畢，故言無不得差也。

Daosheng comments: This symbolizes the five gates of contemplation such as impermanence. Sengliang comments: Further reflecting on the gates of remedy, he severed the fetters of contemplation. Fayao says: The pungent, bitter, and other flavors symbolize contemplations such as impermanence. Earlier, medical formulas and arts were mentioned, describing the beginning of transformation. Here, pungent and bitter are mentioned, narrating the end of the teaching. One stage of affairs being completed, it is therefore said that 'none failed to be cured'.