Hear Twice Before You Speak Once.
Hear twice before you speak once.
Think twice before you speak to a friend in need. -- Ambrose Bierce, "The Devil's Dictionary
It was one of those parties where you cough twice before you speak, and then decide not to say it after all.
-- P. G. Wodehouse...
Heating with wood, you get warm twice: Once chopping it, and once stacking it.
You'll have to speak up if you expect me to hear you.
Think before you speak is criticism's motto; speak before you think, creation's. -- E. M. Forste
Measure twice because you can only cut once.
Measure twice, cut once.
Once bitten, twice shy
Everything comes to him who waits - and in a building with one elevator, it will also be noticed that the thing goes up twice before it comes down once.