WHAT really Gandalf said to Balrog?

[Olmer]

"You can not pass.
I am a Servant of the Secret Fire, wielder of the flame of Anor. You cannot pass.
The dark fire will not avail you, flame of Udun.
Go back to the Shadow!
You cannot pass"
I can't help not to notice the comment on Gandalf's encounter with Balrog.

Bombadillo This paragraph defines the story! It shows how desperate the Felowship's adventure was (notice how Gandalf "said" to the Balrog... He was Weary and didn't want to lift his staff.)...

I put my ideas in a little essay on this subject, where I don't think that Gandalf was weary and didn't want to lift his staff.
But then why he was making some kind of chanting, TALKING to Balrog in the first place instead of doing something?
What was really going on on the bridge?
What the meaning of Gandalf's words?