http://revach.net/article.php?id=3678

Section:  Avodah   Category: 48 Kinyanei Torah
Kinyan 16 Mi'ut Sicha - Rav Elchonon Wasserman Speaks Words That Last For The Ages
Rav Elchonon Wasserman once asked, why is all the Chochma aside from Chochmas HaTorah called Devarim Biteilim?  He answered that all the great wisdom in the world does not last.  One scientist becomes a hero with a theory that is eventually disproved by the next genius, sooner or later.  The world is full of "studies" that last only for a short time.  Wine cures cancer or does it cause it?  Eggs make you healthy or do they kill you?  How did the world begin?  What's in outer space?  The list goes on and on... and the studies keep piling up (dust).

The gemara in Yuma (19b) says that if you speak Sichas Chulin you are oveir on a Mitzvas Aseh!  The Torah says "V'Dibarta Bam", you must speak in Torah and not anything else.  Rashi says this means childish talk and Kalus Rosh.  Could you imagine?  An aveira for speaking things that are not Devarim Asurim!

The Medrash Shmuel says that limiting speech even applies to speaking in learning.  Whenever you can minimize your speech, you should.  We learn this from the torah itself which often teaches halachos with a single extra letter rather than elaborate.

Talk is cheap and silence is golden.  The mishna tells us that if we sing the song of silence we will own the song of Torah.