起信論註 1.2

1.2

□能詮教有此所詮。一心二門三大等法。能起眾生大乘信根。此能詮教決定應說。大乘信者。即信己性知心妄動無前境界（答。則信己性□。則信自許身中心真如□共佛一種則知心□□動無前境界。□中則能猛利永不轉）此信決定能持能長自及餘善故名信根（問。何名能持能長。答。若有眾生信則能增長一切善行故名自及餘善。猶如養一箇小樹。若養得根拔苗自成就故名能持能長）故名信根。

[...] the signifier teaching contains this signified [doctrine]—the teachings of the one mind, the two aspects, the three greatnesses, and so forth—which can arouse the faculty of faith in the Mahāyāna in sentient beings. This signifier teaching definitely should be expounded. Faith in the Mahāyāna means to have faith in one's own nature, knowing that when the mind is deludedly activated there are no external sensory objects. (Answer: That is, having faith in one's own nature [...], having faith that the tathatā of the mind within oneself is of the same kind as the Buddha's; one knows that the mind's [...] activation has no external sensory objects. Within [...] one can be vigorous and never turn back.) This faith definitely can maintain and grow one's own and other wholesome [qualities]; hence it is called the faculty of faith. (Question: What is meant by "can maintain and grow"? Answer: If a sentient being has faith, it can augment all wholesome practices; hence it is called "one's own and other wholesome [qualities]". It is just like raising a small tree: if one can nourish its root, the shoots will naturally be accomplished; hence it is called "can maintain and grow".) Hence it is called the faculty of faith.