大般涅槃經集解 15.43

15.43

案僧亮曰：涉生死之險，如履白刃也。當視人天生怯弱者，生死倒惑無根，譬彼怯弱也。從理生解，有根難動，自譬勇健也。

Sengliang notes: Traversing the perils of saṃsāra is like treading on a naked blade. One should view those among humans and devas who give rise to cowardice: the inverted delusions of saṃsāra have no root, analogized to that cowardice. Generating understanding from principle has roots and is hard to shake, which is self-analogized to bravery.