It would do well if you were to reflect a little before speaking.
6 seconds sound clip from the Mr. Topaze (1961) movie soundboard.
You can hear this line at 01:05:41 in the Blu-ray version of the movie.
Quote context
[...]
- That was a rude and untimely remark.
- It would do well if you were to reflect a little before speaking.
- Would you please leave the room.
- Before I go, I thought you might like to read this.
- It's the monthly report of the city council.
[...]