I'd say it sounded like an ultimatum.
4 seconds sound clip from the Forbidden Planet (1956) movie soundboard.
You can hear this line at 01:12:57 in the Blu-ray version of the movie.
Quote context
[...]
- The Belerephon pattern is being woven again.
- Remain here, and the next attack on your party will be more deadly and general.
- Know? I seem to visualize it. I... If you wish, call it a premonition.
- What do you make of that, skipper?
- I'd say it sounded like an ultimatum.
- I want a clear field of fire in all directions.
[...]
Forbidden Planet (1956) Sound Clip
Actors: Walter Pidgeon (Dr. Edward Morbius), Anne Francis (Altaira "Alta" Morbius), Leslie Nielsen (Commander John J. Adams), Robby the Robot (Marvin Miller)
Trail of the Pink Panther (1982) 526 Sounds / Quotes
The Hunt for Red October 940 Sounds / Quotes
Black Belt Jones (1974) 458 Sounds / Quotes
The Rescuers Down Under (1990) 478 Sounds / Quotes
DuckTales: The Movie (1990) 563 Sounds / Quotes