大般涅槃經集解 65.42

65.42

案僧亮曰：佛意無作非色，以因色生，從因名色。不解佛意，謂無作是色性。

Sengliang comments: The Buddha's intention was that non-manifest [action] is not form; because it arises due to form, it is named 'form' after its cause. Not understanding the Buddha's intention, they thought that non-manifest [action] is material in nature.