Didn’t I hear something like that somewhere else?

[Lostgaeriel]

Hi Beruthiel,

I'm not sure if I've got the "similar" quote, but your original...

‘The hasty stroke goes oft astray’

was said by Aragorn to Gimli, The Return of the King, The Passing of the Grey Company (about the middle of the chapter).

Here are Éowyn & Aragorn a few pages later.

And she answered as one that likes not what is said: 'Then, lord, you are astray; for out of Harrowdale no road runs east or south; and you had best return as you came.'
'Nay lady,' said he, 'I am not astray; for I walked in this land ere you were born to grace it. There is a road out of this valley, and that road I shall take. Tomorrow I shall ride by the Paths of the Dead.'

I can't think of anything closer sounding than this...I doubt it's what you're looking for, though. But my attempt may help someone else figure it out.