Actually, that was Gandalf wanting to use the Palantir out of Isengard.
IIRC, Gandalf said of accepting the Ring (not and exact quote)
“Do not tempt me! For the way of the Ring to my heart is through pity. The struggle would tax my strength, which I’ll have need of. Dark times lie ahead” That’s in The Shadow of the Past, towards the beginning of FOTR.
Well, didn’t they talk in the council of Rivendell about the Legend of the King? That was part of Faramir’s dream, wasn’t it? And they all said that Arangorn was a descendant of the old line of kings. And besides, who else but him? When you know they are talking of a king, which of all the characters could it be, except him? I don’t know, I read the book before the movie and after the Rivendell council I was pretty sure Arangorn was the person of the legend.