大般涅槃經集解 54.213

54.213

案僧亮曰：夫一豪知見皆是佛理，未足者名因性，具足者名果性。性名雖同，具不具異也。僧宗曰：就答中有五重。又明雖復當性，然要須修道也。

Sengliang comments: Every single hair's-breadth of knowledge and vision is the principle of Buddhahood; that which is not yet complete is called the causal nature, while that which is fully complete is called the fruitional nature. Although the name 'nature' is the same, being complete or incomplete differs. / Sengzong says: In the answer there are five layers. It also explains that although they will certainly have the nature, they must nevertheless cultivate the path.