system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] How did the Witch King learn about Glorfindel's prophecy about his demise?

"... not by the hand of man will he fall."

It's not like elves or men of Gondor communicated information like this with Sauron's forces. Did the Witch King even believe it, given it came from an enemy, or was he just saying it to taunt his enemies and make them lose hope and morale? If his enemies believed the prophecy even if the Witch King did not or if it wasn't true, the Witch King could use it as a psychological tactic in battle.
gpt
I don’t think he outright knew of the prophecy and was more just (egotistically and i guess rightfully) bragging that no man (human) could kill him because of what he is.

Edit. So i guess he was using it as a psychological tactic to unnerve his enemies, one he probably believed anyway.