Which sutras are most directly relevant to the virtue of courage?

If I want to read through the origins of western (really, Greek) thought about the virtue we generally call courage, I know exactly where to go: Laches, Republic, Nicomachean Ethics, etc. Meanwhile, while courage has played a central role in many of the dharma talks I've listened to, if someone asked me where to look for a Buddhist theory of courage I wouldn't know any particular place to start. Within the most widely accepted Buddhist scriptures (especially but not limited to the Pali Canon) are there are any "go-to" sutras on the subject of courage? (Especially from a philosophical, psychological, or theoretical standpoint - whether or not that theory is grounded in narrative or discourse.) [This question](https://buddhism.stackexchange.com/questions/25817/compassion-is-a-result-of-knowledge-but-what-about-courage) gives several interesting references for modern writings about courage, but said I'm particularly interested in the older premodern stuff.