大般涅槃經集解 66.10

66.10

案僧亮曰：斷善之與正定，皆由利根。何者？若外親善友則正，若外離善友則斷也。此說斷善之始。第四譬邪見分也。

Sengliang comments: Both the severing of the good and correct determinacy derive from sharp faculties. Why? If externally one stays close to good friends, one becomes correct; if externally one departs from good friends, one severs [the good]. This explains the beginning of severing the good. It is the fourth part, on the analogy of wrong views.