妙法蓮華經玄義 9.97

9.97

例如正因佛性，非因非果，而言是因非果名佛性，是果非因名大涅槃。又佛性非當非本，而言本自有之，一切眾生即涅槃相，不可復滅。又言一切眾生悉有佛性，而實未有三十二相，未來當得金剛之身，以其非當，是故言本；以其非本，是故言當。宗體之義，亦復如是。

For instance, the buddha-nature of direct cause is neither cause nor effect, yet it is said that being cause and not effect is called buddha-nature, and being effect and not cause is called the Great Nirvāṇa. Moreover, buddha-nature is neither future nor original, yet it is said to be originally possessed of itself, and that all sentient beings are themselves the mark of nirvāṇa and cannot be extinguished again. It is also said that all sentient beings have the buddha-nature, yet in reality they do not yet have the thirty-two marks and will in the future attain the vajra-body; because it is not future, it is therefore said to be original; because it is not original, it is therefore said to be future. The meaning of central purport and substance is also just like this.