大方廣佛華嚴經隨疏演義鈔 17.38

17.38

疏「十善財下善友教證分」者，若據標云「隨其本會科」，會各一分，只成九分；欲顯圓十，故開後一。據實合有十會表圓，或經來未盡，且案文釋耳。

Regarding the Commentary's statement, 'Tenth, from Sudhana downward, the Section on the Good Friends' Teaching and Realization': If based on the rubric stating 'division according to its root assembly', each assembly being one section would only make nine sections; wishing to reveal the perfect ten, the latter one is opened up. In reality there should be ten assemblies to represent perfection, or perhaps the sūtra transmission was incomplete, and so it is interpreted provisionally according to the text.