大般涅槃經集解 71.52

71.52

案僧亮曰：答第五難。非因者，正因也。貪有二因者，覺觀是內因、六塵是外因，因內生外。

Sengliang comments: This answers the fifth objection. 'Not due to' refers to the primary cause. That greed has two causes means that investigation and reflection are the internal cause, and the six sense objects are the external cause; relying on the internal, the external is produced.