A palantir is a dangerous tool, Saruman.
5 seconds sound clip from the The Lord of the Rings: The Fellowship of the Ring movie soundboard.
You can hear this line at 00:48:42 in the Blu-ray version of the movie.
Quote context
[...]
- A Great Eye, lidless, wreathed in flame.
- He is gathering all evil to him.
- Very soon, he'll have summoned an army great enough to launch an assault upon Middle-earth.
- A palantir is a dangerous tool, Saruman.
- Why? Why should we fear to use it?
- They are not all accounted for, the lost Seeing-stones.
- We do not know who else may be watching.
- The hour is later than you think.
- Sauron's forces are already moving.
[...]