大乘起信論裂網疏 5.80

5.80

此正明頓教初發心人，即已住正定聚，畢竟不退也。蓋不唯初發心住有此勝力，但得決定實信，知一切法本性涅槃，亦不同權教發心或墮二乘矣。初釋信成就發心竟。

This directly clarifies that a person of the sudden teaching who first arouses the mind has already abided in the group of the definitely settled and is ultimately non-retrogressing. It is not only that the stage of first arousing the mind possesses this superior power; anyone who merely attains decisive, true faith and knows that all phenomena are by nature nirvāṇa also differs from those who arouse the mind in the provisional teaching who may fall into the two vehicles.

The first section, explaining the arousal of the mind upon perfecting faith, is concluded.