Luke... Luke, do not... Do not underestimate the powers of the Emperor, or suffer your father's fate you will.
18 seconds sound clip from the Star Wars: Episode VI - Return of the Jedi movie soundboard.
You can hear this line at 00:43:33.863 in the Blu-ray version of the movie.
Quote context
[...]
- Remember, a Jedi's strength flows from the Force.
- But beware... Anger, fear, aggression, the dark side are they.
- Once you start down the dark path, forever will it dominate your destiny.
- Luke, when gone am I, the last of the Jedi will you be.
- Luke, the Force runs strong in your family.
- Pass on what you have learned.
- Luke... there is... another... Skywalker.
[...]