大般涅槃經義記 8.198

8.198

下解名義。「首楞事竟，嚴名堅」者，翻名解義。「畢竟而堅名首楞嚴」牒以結之。「以是首楞名佛性」者，結首楞嚴以為佛性。以能造作果德事竟，故名佛性。

Below, the meaning of the name is explained: "*Śūraṃ* means 'matters accomplished,' and *gama* means 'firm'" translates the name and explains its meaning. "Ultimate and firm is called Śūraṅgama" takes this up and concludes it. "Because of this, the Śūraṅgama is called buddha-nature" concludes that the Śūraṅgama is the buddha-nature: because it can bring the matters of the fruitional virtues to accomplishment, it is called buddha-nature.